* Ensure that scripts without the notion of upper/lower case can create du identifiers

* Feedback and improvements

* feedback

* correct comment

* # This is a combination of 9 commits.
# This is the 1st commit message:

ref -> mutable in more places in the compiler

# The commit message #2 will be skipped:

# Update dependencies from https://github.com/dotnet/arcade build 20191229.1
#
# - Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.19629.1

# The commit message #3 will be skipped:

# Update dependencies from https://github.com/dotnet/arcade build 20191230.1
#
# - Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.19630.1

# The commit message #4 will be skipped:

# Update dependencies from https://github.com/dotnet/arcade build 20191231.1
#
# - Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.19631.1

# The commit message #5 will be skipped:

# Update dependencies from https://github.com/dotnet/arcade build 20200101.1
#
# - Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20051.1

# The commit message #6 will be skipped:

# Update dependencies from https://github.com/dotnet/arcade build 20191216.5 (#8079)
#
# - Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19616.5

# The commit message #7 will be skipped:

# dispose fsi at the end of a scripting session (#8084)
#

# The commit message #8 will be skipped:

# Added static link tests and extended CompilerAssert (#8101)
#
# * Changed CompilerAssert to static class. Added Compile/Execute methods that take a Compilation description. Added static link tests
# 
# * Hiding compilation description internals
# 
# * Added another test to check for sanity
# 
# * Making a few optional parameters
# 
# * Hiding internals of CompilationReference

# The commit message #9 will be skipped:

# Parameterize product version (#8031)
#
# * Parameterize Product details
# 
# * fcs
# 
# * Repack pkgdef

* no ilread

* Set LOH threshold for chunked resizearray to be smaller to avoid LOH allocations

* Update illib.fs

* Removed UnicodeFileAsLexbuf. Replaced it with StreamReaderAsLexbuf. No longer allocating string and chars as a result.

* Make these private

* Update FSharp.Core to netstandard2.0

* Remove netstandard1.6 feature flags

* default.w32manifest

* default.w32manifest

* Uniform TryGetValue usage

* Removed extra parenthesis

* Remove parenthesis

* update FCS dependencies

* update FCS dependencies

* fix up build

* code review

* spacing for commas and colons

* code review

* cleanup semicolons (ugh)

* fix build

* a little more cleanup

* little bit more cleanup

* little bit more cleanup

* little bit more documentation

* little bit more docs

* whitespace cleanup and docs

* more whitespace and code formatting

* little bit more docs

* add diagnostics

* add diagnostics

* add diagnostics

* diagnostics

* diagnostics

* diagnostics

* add diagnostics and possible fix for tp smoke tests

* fix build

* fix build

* Microsoft.FSharp.Comiler --> FSharp.Compiler

* Microsoft.FSharp.Build --> FSharp.Build

* fix small mistakes

* fix build

* fix flakey test (?)

* chunkify TcSymbolUseData

* move LOH size out to a constant

* do chunking and mapping together to reduce allocations

* clarify comment around GC impacts

* add comment informing others of the potential for LOH allocations

* Remove dependence on runfsc.cmd and runfsc.sh (#5882)

* Remove dependence on runfsc.cmd and runfsc.sh

* White space

* Add TryExactlyOne for array, list and seq. (#5804)

* FS-1065 Value Option Parity (#5772)

* Initial FS-1065 implementation

* Undo removal of compilationrepresentation suffix and update surface area

* Whoopise, add the suffix to the impl file

* Update coreclr surface area

* Revert the FSComp changes that somehow got picked up

* newline

* Consume internal VOption module functions

* More internal voption module functions

* Initial FS-1065 implementation

* Undo removal of compilationrepresentation suffix and update surface area

* Whoopise, add the suffix to the impl file

* Update coreclr surface area

* Revert the FSComp changes that somehow got picked up

* newline

* Consume internal VOption module functions

* More internal voption module functions

* Remove second internal ValueOption

* Update FSharp.Core in FCS

* Cleanup

* Remove old TryGetValue

* Reduce use of TryFind

* Reduce allocations in TcPatBindingName

* Reduce some allocations in NameResolution

* Reduce some allocations in TypeChecker

* Use latest FSharp.Core in FCS

* Update FSharp.Core in FCS

* We only need to check for mangledGenericTypeNameSym once

* ShortCut name checking

* Reduce number of LastIndexOf calls

* Reduce number of LastIndexOf calls

* Reduce number of LastIndexOf calls

* Incorporate feedback

* Use PrettyNaming.DemangleGenericTypeName instead of ungenericizeTypeName

* Remove couple of double checks

* Update illib.fs

* Use ordinal string comparison in string manipulation methods

StartsWith, EndsWith, Compare, etc

* Add StartsWithOrdinal, EndsWithOrdinal extension methods

* replace List.chop with List.splitAt

remove List.take from illib.fs

* replace List.splitAt >> fst with List.take

* use List.truncate instead of List.take

* Revert "replace List.splitAt >> fst with List.take"

This reverts commit c4f06057724f6e2fc7c85c49c236903352ac629f.

* Revert "Revert "replace List.splitAt >> fst with List.take""

This reverts commit 2cb969341dc6031e63856db314671f5969db7aeb.

* Revert "replace List.chop with List.splitAt"

This reverts commit cde206bd17de9e4724c949c3c4f77ff2864af23e.

# Conflicts:
#	src/fsharp/SignatureConformance.fs

* remove List.take from illib.fs and replace its usages with List.truncate

* Revert "remove List.take from illib.fs and replace its usages with List.truncate"

This reverts commit 8a198b0334ada7990f5804afe800b89915b69d46.

# Conflicts:
#	src/fsharp/DetupleArgs.fs

* Revert "Revert "remove List.take from illib.fs and replace its usages with List.truncate""

This reverts commit 6722f08faae33b6b8262f67482385a81f3616dcd.

* rollback accidental change

* Update README.md

* Update README.md

* Update README.md

* [RFCs FS-1051, FS-1052, FS-1053] support for span, readonly refs, byref-like structs (#4888)

* initial support for span, readonly refs, byref-like structs

* fix proto build

* make proto work with previous FSharp.Core

* make proto work with previous FSharp.Core

* update baselines

* integrate code cleanup

* integrate code cleanup

* integrate code cleanup

* integrate code cleanup

* fix build

* fix build

* implicit deref of byref returns

* add tests for Memory, ReadOnlySpan and ReadOnlyMemory

* fix tests

* simplify diff

* simplify diff

* remove duplicate error messages

* fix build

* test updates

* fix build

* fix build

* update baselines

* fix uses of NativePtr.toByRef

* switch to inference using byref pointer capabilities

* fix proto build

* update baselines, byref extension methods

* fix test errors

* emit in,out,modreq attributes correctly

* update tests

* fix build

* fix build

* fix tests

* fix tests

* get it right silly boy

* fix test

* minor cleanup

* add more tests

* clarify overloading behaviour + test case

* fix build break

* fix build of tests

* update tests

* add more tests

* byref fixes

* updates for subsumption calls, error message, assign-to-return-byref

* test updates, implicit deref on byref return for normal functions

* update baseline

* improve debug formatting, better error message on implicit deref, improve error messages

* add more tests for recursive functions

* update baselines

* fix baselines

* updates for new test cases

* updates for new test cases

* test updates and byref-to-byreflike

* deal with 'M() <- expr'

* restrict addresses of immutable top-level things

* fix IsByRefLike on struct

* update tests

* fix test

* fix test

* improve check for no-return-of-struct-field-addresses

* fix test case

* Provide fast generic comparer for bool values (#5076)

* provide fast generic comparer for bool values

* formatting

* no completion on name of value and function declaration (#5083)

* LOC CHECKIN | Microsoft/visualfsharp master | 20180604 | Termchange (#5082)

* fix merge

* initial support for span, readonly refs, byref-like structs

* fix proto build

* make proto work with previous FSharp.Core

* make proto work with previous FSharp.Core

* update baselines

* integrate code cleanup

* integrate code cleanup

* integrate code cleanup

* integrate code cleanup

* fix build

* fix build

* implicit deref of byref returns

* add tests for Memory, ReadOnlySpan and ReadOnlyMemory

* fix tests

* simplify diff

* simplify diff

* remove duplicate error messages

* fix build

* test updates

* fix build

* fix build

* update baselines

* fix uses of NativePtr.toByRef

* switch to inference using byref pointer capabilities

* fix proto build

* update baselines, byref extension methods

* fix test errors

* emit in,out,modreq attributes correctly

* update tests

* fix build

* fix build

* fix tests

* fix tests

* get it right silly boy

* fix test

* minor cleanup

* add more tests

* clarify overloading behaviour + test case

* fix build break

* fix build of tests

* update tests

* add more tests

* byref fixes

* updates for subsumption calls, error message, assign-to-return-byref

* test updates, implicit deref on byref return for normal functions

* update baseline

* improve debug formatting, better error message on implicit deref, improve error messages

* add more tests for recursive functions

* update baselines

* fix baselines

* updates for new test cases

* updates for new test cases

* test updates and byref-to-byreflike

* deal with 'M() <- expr'

* restrict addresses of immutable top-level things

* fix IsByRefLike on struct

* update tests

* fix test

* fix test

* improve check for no-return-of-struct-field-addresses

* fix test case

* filter out duplicates in GetOpenDeclarations

* Add rec module to unused opens test

* add unused opens tests for rec modules

* fix unused opens for rec modules

* filter out symbol uses that lays above the open statement

* filter out union cases definitions

* fix ItemsAreEffectivelyEqualHash for Item.ModuleOrNamespaces

* use Dictionary to lookup symbol uses by declaring entity

* formatting

* cleanup

* use Dictionary to filter out already processed modules

* add BagAdd and BagExistsValueForKey Dictionary extensions

* Fixing #4967 (#4968)

* Fix internal error when compiling interface implementation lacking an overloaded method implementation - fixes #4967

* Adding a test

* Update E_OverloadMismatch.fs

* Remove a setify + isSingleton combo (#4980)

* remove a setify

* Remove intermediate collection

* Improve async stack traces (#4867)

* very early prototype

* async stack traces

* async cleanup

* minor fix

* async cleanup

* more async cleanup

* integrate async-cleanup

* async cleanup

* fix build

* more cleanup

* minor fixes

* minor fixes

* full exception stacktraces

* fix test

* fix test

* code review

* cleanup naming

* fix build

* undo rethrow and integrate cleanup

* apply renamings

* Further cleanup in control.fs

* add tests and add filtering TryWith, plus other cleanup

* integrate cleanup

* fix tests

* test only runs on .net framework

* slightly tweak primitives to be more suitable for later optimization

* slightly tweak primitives to be more suitable for later optimization

* update baselines

* add check that no line 0 appear in stack

* update baseline

* use struct wrapper for async activation

* simplify code

* simplify code

* update baselines

* update baselines

* fix baseline

* remove dead code

* simplify code

* apply DebuggerHidden in a couple more places

* [ RFC FS-1039] implementation of value options (#4837)

* posible implementation of value options

* fix surface area test

* fix test

* VNone --> ValueNone

* fix surface area

* fix build

* update baselines

* fix baselines

* fix baselines

* fix baselines

* fix baselines

* fix build

* posible implementation of value options

* fix surface area test

* fix test

* VNone --> ValueNone

* fix surface area

* fix build

* update baselines

* fix baselines

* fix baselines

* fix baselines

* fix baselines

* fix build

Thanks for this.

* Reduced allocation by reading from a stream into an array for ILResource

* GetRawFSharpSignatureData is now lazy getting bytes. This is what GetRawFSharpOptimizationData does

* Using File.ReadBinaryChunk

* Reduced allocation by reading from a stream into an array for ILResource

* GetRawFSharpSignatureData is now lazy getting bytes. This is what GetRawFSharpOptimizationData does

* Using File.ReadBinaryChunk

* weak ByteFile

* cleanup, only use in VS

* cleanup flags

* some comments

* some comments

* use Roslyn memory manager for metadata in VS

* report statistics only with --times, clarify flags2

* minor updates

* us in VS

* fix build

* fix build

* fix build

* add SFH to FileSystem

* fix build

* fix build

* fix build

* fix build

* add some comments

* clean option module in illib

* Update NicePrint.fs

* Update NicePrint.fs

* Update NicePrint.fs

* Update NicePrint.fs

* Update NicePrint.fs

* rename src/fsharp/vs --> src/fsharp/service

* move unit tests to tests"

* remove some namespace opens

* remove COMPILER_PUBLIC_API

* remove COMPILER_PUBLIC_API