The _password field is not needed since CryptDeriveKey was not ported
from the Desktop framework.

Removing the field also allows removing a defensive copy and clearing it
during disposal.

* BigInteger changes

* sq

* Runtime side unit tests

* Half tests

* Address feedback

* sq

* Move to a ThrowHelper class

* Move to invariant number format

* Move to canonical throw

* sq

* sq

* Fix bad unicode char

* Add the percent tests back

This checkin adapts the mark list logic for regions.

The basic idea is that as plan_phase goes through the regions, it calls get_region_mark_list obtain the mark list for each region.

How get_region_mark_list works is different for WKS and SVR flavors of the GC:

 - for WKS, we have a single sorted mark list. Finding the mark list section corresponding to a region is done via binary search in the mark list.

 - for SVR, each GC thread, after sorting the mark list, determines where the sections corresponding to all the regions start and end. This is stored in tables mark_list_piece_start and mark_list_piece_end which are now indexed by region number. Later, get_region_mark_list merges the pieces for a region from all heaps. This is very similar to what merge_mark_lists did before.

Add new Task-based UDP socket methods and reimplement existing ones using SocketAsyncEventArgs (#47229)

Closes #41502, but does not change the existing APM methods

Microsoft.NET.ILLink.Tasks
 From Version 6.0.0-alpha.1.21075.2 -> To Version 6.0.0-alpha.1.21076.1
Co-authored-by: Ndotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

* test WindowsIdentityImpersonatedTests runs

* fix win8

* add test variant

* final cleanup

Funnel PGO instrumentation data from runtime to crossgen2

- Representation of instrumentation data within crossgen2 and dotnet-pgo
- New uncompressed mibc format for easier debugging/faster processing
- Storage of instrumentation data in mibc file
- Parser for instrumentation data to load from mibc file
- Translation of crossgen2 in memory representation of instrumentation data from managed form to jit

Future PGO work will include
- Instrumentation data storage and extraction from R2R files
- 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

• Avoid double-writing of crossgen2\clrjit_win_x64_x64.dll file.
• Avoid extra slashes in paths.

As a prerequisite to enabling efficient instrumentation, add instrumentation
immediately after importing, so the flow graph more closely reflects the IL
level view.

* Use SHash instead of CClosedHash for ILStubCache
* Use updated stub flags (taking into account SuppressGCTransition) when caching
* Add tests

Adds a case for `DW_CFA_offset_extended` to `mono_print_unwind_info`,
which avoids a crash when running the runtime with high verbosity.

Initializes the LLVM JIT with LLVM-detected host CPU features.
Unconditionally enables all detected features, instead of using only the
subset supported in `mono_llvm_get_cpu_features`.

* Implement Activity.GetTagItem

* Address the feedback

Build ID 20210126.5

Contributes to #45623

The goal of this PR is change the current files to support the implementation of iCorDebug on mono:

- Split debugger-agent into debugger-protocol and debugger-agent, debugger-protocol will be used in the next PR in mscordbi implementation.
- Fix strings with the meaning of the commands, there were missing strings and then the PRINT_DEBUG_MSG was printing wrong information.
- On debugger-engine pass the offset of the IL when stop in a breakpoint.
- Created a new protocol major version to support the changes that we need to implement mscordbi.
- When mono debugger is started with server=n will waint until the timeout for a server to connect, this is necessary because depending on how we will launch the process with iCorDebug implementation, maybe mono will start before the debugger server(mscordbi).

* Calculate loopSize based on post align adjusted size

* Review comments

Remove `paddingNeeded` as we can get that value from `idCodeSie()`.

* Inline "stp q-reg, q-reg, addr-reg" for frames >= 32 bytes

* Use a pair of "stp q-reg, q-reg, addr-reg" in a loop that clears 64 bytes per iteration for frames >= 192 bytes

* Use dc zva instruction when the instruction is permitted and its block size is set to 64 bytes for frames >= 256 bytes

I couldn't find a single occurence of `[]::` in the test tree, so I assume we don't have any coverage for this.

Arrays are normally allocated with the dedicated `newarr` IL instruction. The ECMA-335 specification says "All zero-based, one-dimensional arrays are created using newarr, not newobj.". Nevertheless, they do have a constructor and apparently code out there uses it.

Also adding coverage for the constructor that creates a jagged array.

Regression test for https://github.com/dotnet/runtimelab/issues/578.

Fixes #47426

Use a separate thread for tiered compilation background work

- Makes it easier to manage how much time is spend for performing background work like rejitting and allows yielding more frequently with just Sleep without incurring thread pool overhead, which is useful in CPU-limited cases
- A min/max range is determined for how long background work will be done before yielding the thread. The max is the same as before, 50 ms. For now the min is `processor count` ms (capped to the max), such that in CPU-limited cases the thread would yield more frequently in order to not monopolize too much of the limited CPU resources for background work, and in cases with a larger number of processors where the background work is typically less intrusive to foreground work it would yield less frequently.
- At the same time, progress should be made on background work such that steady-state perf would be reached in reasonable time. Yielding too frequently can slow down the background work too much. The sleep duration is measured to identify oversubscribed situations to yield less frequently and make faster progress on the background work.
- Due to less time spent rejitting in some CPU-limited cases, steady-state performance may be reached a bit later in favor of fewer spikes along the way
- When the portable thread pool is enabled, a side effect of using a managed worker thread for tiering background work was that several GC-heavy microbenchmarks regressed. Tiering was the only thing using the thread pool in those tests and stack-walking the managed thread was slower due to the presence of GC refs. It's not too concerning, the benchmarks are just measuring something different from before, but in any case this change also resolves that issue. Fixes https://github.com/dotnet/runtime/issues/44211.

Co-authored-by: Ndotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

* Performance tuning Xoshiro pseudo random number generators. Move PRNG state from the heap onto the stack before performong PRNG generation and mxing operations.

* Declare PRNG state method variables on single line (code review feedback nit).

* [wasm] Handle Top-Level style entry point mangling too

This adds a check for '<Main>$' in addition to 'Main' when
looking for the async entry point.

Fixes #47404

When `libgdiplus` is installed via macports, `System.TypeInitializationException` exception is thrown.
This is because macports installs the library in `/opt/local/lib`.

```sh
$ port install libgdiplus
$ port contents libgdiplus
Port libgdiplus contains:
  /opt/local/lib/libgdiplus.0.dylib
  /opt/local/lib/libgdiplus.a
  /opt/local/lib/libgdiplus.dylib
  /opt/local/lib/pkgconfig/libgdiplus.pc
  /opt/local/share/doc/libgdiplus/AUTHORS
  /opt/local/share/doc/libgdiplus/COPYING
  /opt/local/share/doc/libgdiplus/ChangeLog
  /opt/local/share/doc/libgdiplus/LICENSE
  /opt/local/share/doc/libgdiplus/NEWS
  /opt/local/share/doc/libgdiplus/README.md
  /opt/local/share/doc/libgdiplus/TODO
```

PR adds `/opt/local/lib/libgdiplus.dylib` as a well-known probing path.

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Co-authored-by: Nvargaz <vargaz@users.noreply.github.com>

* Fix for issue 46529
Move check for side-effect and don't push the cast for shifts of 32 to 63
Added test Runtime_46239.cs

* clang format

* Fix #46123 - make `subProtocol` nullable when dealing with WebSockets in HttpListener.

* Update ref for System.Net.HttpListener

Create a number of smaller files with cohesive sets of methods.

* Debugging Crossgen2 documentation and such
- Also new --print-repro-instructions command line switch to crossgen2 as requested by the JIT team

Improve support for user-specified Accept-Encoding encodings
Co-authored-by: NStephen Toub <stoub@microsoft.com>
Co-authored-by: NStephen Toub <stoub@microsoft.com>
Co-authored-by: NStephen Toub <stoub@microsoft.com>

Get rid of StreamWriter usage in HTTP loopback server and fix HTTP/1.1 loopback implementation of SendResponseBodyAsync (#47364)

Get rid of StreamWriter usage in HTTP loopback server and fix HTTP/1.1 loopback implementation of SendResponseBodyAsync 
Co-authored-by: NGeoffrey Kizer <geoffrek@windows.microsoft.com>