* Backport docs for System.IO.Compression.Brotli

* Addressed PR suggestions and fixed additional bugs.

* Address feedback.
Enable GenerateDocumentationFile.

* BrotliStream.ReadByte docs.

* BrotliStream.Flush docs.

* BrotliStream.WriteByte docs.

* Replace appname includes to plain text.
Co-authored-by: Ncarlossanlop <carlossanlop@users.noreply.github.com>

* Change C# names of P/Invokes of objc_msgSend to be call-site specific.

* Rename to match suggested pattern

* Follow Xamarin convention in all objc_msgSend cases.

* Fix typo

* Rename to match convention.

[master] Update dependencies from dotnet/icu dotnet/arcade dotnet/runtime dotnet/llvm-project dotnet/xharness (#47762)

* Update dependencies from https://github.com/dotnet/icu build 20210118.1

Microsoft.NETCore.Runtime.ICU.Transport
 From Version 6.0.0-alpha.1.21061.1 -> To Version 6.0.0-alpha.1.21068.1

* Update dependencies from https://github.com/dotnet/arcade build 20210118.2

Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.GenAPI , Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.GenFacades , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.SharedFramework.Sdk , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk
 From Version 2.5.1-beta.21062.10 -> To Version 2.5.1-beta.21068.2

* Update dependencies from https://github.com/dotnet/arcade build 20210119.2

Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.GenAPI , Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.GenFacades , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.SharedFramework.Sdk , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk
 From Version 2.5.1-beta.21068.2 -> To Version 2.5.1-beta.21069.2

* Update dependencies from https://github.com/dotnet/arcade build 20210121.2

Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.GenAPI , Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.GenFacades , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.SharedFramework.Sdk , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk
 From Version 2.5.1-beta.21069.2 -> To Version 2.5.1-beta.21071.2

* Update dependencies from https://github.com/dotnet/runtime build 20210124.3

Microsoft.NETCore.DotNetHost , Microsoft.NETCore.DotNetHostPolicy , Microsoft.NETCore.ILAsm , runtime.native.System.IO.Ports , Microsoft.NET.Sdk.IL , System.Runtime.CompilerServices.Unsafe , System.Text.Json
 From Version 6.0.0-preview.2.21076.5 -> To Version 6.0.0-preview.1.21074.3

* Update dependencies from https://github.com/dotnet/xharness build 20210125.1

Microsoft.DotNet.XHarness.CLI , Microsoft.DotNet.XHarness.TestRunners.Xunit
 From Version 1.0.0-prerelease.21068.3 -> To Version 1.0.0-prerelease.21075.1

* Update dependencies from https://github.com/dotnet/xharness build 20210125.2

Microsoft.DotNet.XHarness.CLI , Microsoft.DotNet.XHarness.TestRunners.Xunit
 From Version 1.0.0-prerelease.21075.1 -> To Version 1.0.0-prerelease.21075.2

* Update dependencies from https://github.com/dotnet/xharness build 20210126.1

Microsoft.DotNet.XHarness.CLI , Microsoft.DotNet.XHarness.TestRunners.Xunit
 From Version 1.0.0-prerelease.21075.2 -> To Version 1.0.0-prerelease.21076.1

* Update dependencies from https://github.com/dotnet/llvm-project build 20210125.1

runtime.osx.10.12-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.win-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.win-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.osx.10.12-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.linux-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.linux-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.linux-arm64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.linux-arm64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk
 From Version 9.0.1-alpha.1.21068.1 -> To Version 9.0.1-alpha.1.21075.1

* Update dependencies from https://github.com/dotnet/icu build 20210125.1

Microsoft.NETCore.Runtime.ICU.Transport
 From Version 6.0.0-alpha.1.21068.1 -> To Version 6.0.0-alpha.1.21075.1

* Update dependencies from https://github.com/dotnet/arcade build 20210122.6

Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.GenAPI , Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.GenFacades , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.SharedFramework.Sdk , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk
 From Version 2.5.1-beta.21071.2 -> To Version 2.5.1-beta.21072.6

* Update dependencies from https://github.com/dotnet/xharness build 20210126.2

Microsoft.DotNet.XHarness.CLI , Microsoft.DotNet.XHarness.TestRunners.Xunit
 From Version 1.0.0-prerelease.21076.1 -> To Version 1.0.0-prerelease.21076.2

* Update dependencies from https://github.com/dotnet/icu build 20210126.3

Microsoft.NETCore.Runtime.ICU.Transport
 From Version 6.0.0-alpha.1.21075.1 -> To Version 6.0.0-preview.2.21076.3

* Update dependencies from https://github.com/dotnet/arcade build 20210126.1

Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.GenAPI , Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.GenFacades , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.SharedFramework.Sdk , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk
 From Version 2.5.1-beta.21072.6 -> To Version 2.5.1-beta.21076.1

* Update dependencies from https://github.com/dotnet/arcade build 20210128.12

Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.GenAPI , Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.GenFacades , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.SharedFramework.Sdk , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk
 From Version 2.5.1-beta.21076.1 -> To Version 2.5.1-beta.21078.12

* Update dependencies from https://github.com/dotnet/xharness build 20210131.1

Microsoft.DotNet.XHarness.CLI , Microsoft.DotNet.XHarness.TestRunners.Xunit
 From Version 1.0.0-prerelease.21076.2 -> To Version 1.0.0-prerelease.21081.1

* Update dependencies from https://github.com/dotnet/runtime build 20210201.2

Microsoft.NETCore.DotNetHost , Microsoft.NETCore.DotNetHostPolicy , Microsoft.NETCore.ILAsm , runtime.native.System.IO.Ports , Microsoft.NET.Sdk.IL , System.Runtime.CompilerServices.Unsafe , System.Text.Json
 From Version 6.0.0-preview.1.21074.3 -> To Version 6.0.0-preview.2.21101.2

* Update dependencies from https://github.com/dotnet/icu build 20210201.12

Microsoft.NETCore.Runtime.ICU.Transport
 From Version 6.0.0-preview.2.21076.3 -> To Version 6.0.0-preview.2.21101.12

* Update dependencies from https://github.com/dotnet/llvm-project build 20210201.1

runtime.osx.10.12-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.win-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.win-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.osx.10.12-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.linux-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.linux-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.linux-arm64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.linux-arm64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk
 From Version 9.0.1-alpha.1.21075.1 -> To Version 9.0.1-alpha.1.21101.1

* Update dependencies from https://github.com/dotnet/arcade build 20210131.1

Microsoft.DotNet.XUnitExtensions , Microsoft.DotNet.VersionTools.Tasks , Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk , Microsoft.DotNet.Build.Tasks.Packaging , Microsoft.DotNet.Build.Tasks.Installers , Microsoft.DotNet.Build.Tasks.Feed , Microsoft.DotNet.Build.Tasks.Archives , Microsoft.DotNet.Arcade.Sdk , Microsoft.DotNet.ApiCompat , Microsoft.DotNet.CodeAnalysis , Microsoft.DotNet.XUnitConsoleRunner , Microsoft.DotNet.GenFacades , Microsoft.DotNet.GenAPI , Microsoft.DotNet.RemoteExecutor , Microsoft.DotNet.Helix.Sdk , Microsoft.DotNet.SharedFramework.Sdk
 From Version 6.0.0-beta.21078.12 -> To Version 6.0.0-beta.21081.1

* Update dependencies from https://github.com/dotnet/xharness build 20210202.1

Microsoft.DotNet.XHarness.CLI , Microsoft.DotNet.XHarness.TestRunners.Xunit
 From Version 1.0.0-prerelease.21068.3 -> To Version 1.0.0-prerelease.21102.1
Co-authored-by: Ndotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

* Resolve ILLink warnings in System.Linq.Expressions (Round 1)

Contributes to #45623

* Address PR feedback

* PR feedback

* Clean up old Makefile-based build system from src/mono

Everything is using CMake now.

* Fix extraction of MONO_CORLIB_VERSION from configure.ac

Move the version into CMakeLists.txt

Microsoft.NETCore.Runtime.ICU.Transport
 From Version 6.0.0-alpha.1.21061.1 -> To Version 6.0.0-preview.2.21101.12
Co-authored-by: Ndotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

- Set to 0x112 as in readytorun.h
- Resolve assertion in LoadDynamicInfoEntry vm/jitinterface.cpp

Fixes #47637, and adds ReceiveSent_UDP_Success test to both ReceiveFrom and ReceiveMessageFrom

runtime.osx.10.12-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.win-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.win-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.osx.10.12-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.linux-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.linux-x64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk , runtime.linux-arm64.Microsoft.NETCore.Runtime.Mono.LLVM.Tools , runtime.linux-arm64.Microsoft.NETCore.Runtime.Mono.LLVM.Sdk
 From Version 9.0.1-alpha.1.21064.1 -> To Version 9.0.1-alpha.1.21068.1
Co-authored-by: Ndotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

Update build and README to use `hotreload-delta-gen` from [hotreload-utils](https://github.com/dotnet/hotreload-utils)

Co-authored-by: NAleksey Kliger (λgeek) <akliger@gmail.com>

* adding span version of ReceiveMessageFrom

fix #43933

* Started using new testsetup for the receivemessagefrom

* removed code duplication in socketpal.windows

* removed unused buffers parameter

* adding non-zero offset to the ReceiveMessageFrom test

* added documentation

* offset fix for EAP tests

* fixing pr comments

This fixes a problem where accidentally too much code was excluded with USE_REGIONS.

This caused the compaction decision to be inconsistent between heaps, with some heaps doing compacting and some heaps doing mark&sweep. This is a problem, because the relocation phase relies on relocation information stored in the free space between used objects, and the free space is being overwritten by the sweep. It's an issue only for object pointers between heaps, but these are very common.

* Produce a .version file for Microsoft.NETCore.App in the runtime layout.

* Update src/installer/pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.sfxproj

* Update src/installer/pkg/sfx/Microsoft.NETCore.App/Microsoft.NETCore.App.Runtime.sfxproj

Use it to take the slow path in metadata lookups when there's at least one
delta applied.

Change #47646 did not remove the code in `fgMakeBasicBlocks` that set profile
data. That masked some flaws in `fgIncorporateProfileData`:
* it should process all blocks; nothing has been imported yet
* it must honor a constraint that some handler blocks can't be rare.

This fixes the above, and removes the early profile setting.

- Fix class type probes (the increment of the count wasn't correct)
- Use the 64bit integer encoders for all the pgo data
- New section for R2R PE Files containing instrumentation data
- R2RDump functionality to display all the data embedded in the file
- Enable BBOPT for optimized builds in a more unconditional fashion

Future PGO work will include
- Move Pgo type handle histogram processing into JIT (which will make type guessing work in crossgen2 as well as in the runtime)
- Triggers for controlling Pgo data extraction
- Size control for pgo instrumentation data

With this checkin, the feature is functional from a crossgen2.exe point of view, but its not polished, and it cannot be used from the Crossgen2 sdk integration yet (as the sdk does not have the ability to pass an extra pair of arguments to the compiler. 

The DisableCertificateDownloads property on the chain policy controls all
network activity when building a chain on macOS, not just AIA fetching. If
set to true, the (default) revocation policy would fail because the network
would be treated as unavailable. On macOS, as a work around, permit the
network activity if revocation checking is explicitly enabled.

PLINQ's QueryTaskGroupState handles joining with queued tasks, and handles the exceptions that emerge from waiting on them.  AggregateExceptions are special-cased, and are flattened to eliminate extra levels that may have been added explicitly or implicitly; the code then checks to see whether all of the exceptions contained in the aggregate represent cancellation.  However, it fails to account for the possibility that there are no exceptions it contains, which could happen if the only exceptions thrown are themselves empty AggregateExceptions.  If that happens, the code makes some invalid assumptions that lead to a failed assert and then throwing an ObjectDisposedException.

The fix is just to check whether the flattened AggregateException is empty and to treat that not as cancellation but as a normal exception.

Uses the recently added support for SocketsHttpHandler.ConnectCallback to be used for synchronous operations to add support for HttpWebRequest.ReadWriteTimeout.  That value is now used to set the Read/WriteTimeout on the underlying socket, with it then affecting all synchronous reads and writes on that connection.  The ReadWriteTimeout is added to the cache key for whether the cached HttpClient instance can be used, as is whether the request is sync or async because that influences how connections are created from the HttpClient instance.

* Update license headers in new files

* Run dotnet-format on changeset

* Add support for EventPipe stackwalks and method formatting on Mono.

* Review feedback.

* Explicit gboolean -> bool conversion.

* Add test validating against regression in #46469

* fix test bug

It's strictly speaking not required but the type is handled by
JIT specially and illink would need to recognize this one of case.

* Issue-20619 early return existing value.

* issue-20619 Fix comment: Reuse check inside of SetItem; Also use customer-supplied value comparer for TryUpdate().

* issue-20619 Fix tab-space issue.

* issue-20619 Fix comment: Revert: use customer-supplied value comparer for TryUpdate().

* Remove duplicated unwind and GC info table entries.
* Overall, reduces the framework size with CG2 by 2.4MB (89,835,064 -> 87,439,416 bytes)

This error was introduced in my last PR about icordebug implementation. Fixing it as @lambdageek told me that it was reported on coverity scan.
Co-authored-by: Nthaystg <thaystg@users.noreply.github.com>

Instead of trying to set block weight data when initially building the
flowgraph, do it as a phase just before importation.

The importer looks at block weights, so these must be set before importation.

Note profile incorporation relies only on the IL level view of the method,
and does not depend on the IR.