Key problem with the tests is they were being run in parallel. This is
due to using CoreClr which doesn't respect our .config based options.

Also fixed bad uses of Thread.Abort in the try finally tests which were
causing resource cleanup issues

147 failures remaining to handle

This updates the CoreClr test infrastructure to include verifying the
metadata signaturse of the emitted code. There is not 100% parity due to
the inability to read custom attribute data on parameters, fields, etc
... But that covers only a small number of test cases.

Destructor tests now passing.

Needed the split between the netstandand and desktop version of the
reference to be more explicit.

The ability to verify IL is presently a runtime specific operation.
Moved the logic to enforce the test conforms to the specified behavior
into the runitme layers.

* Refactor Windows PDB writer

Move checking of structure-options to a common location (so it will be picked up by all roslyn languages).

* Move common parts of Microsoft.CSharp.Core.targets and Microsoft.VisualBasic.Core.targets to Microsoft.Managed.Core.targets

Merge 15.7.x features/compiler work into the dev15.7.x 

* enable logAnalyzerExecutionTime on IDE so that we can start track analyzer perf

* removed unnecessary ICodeAnalysisDiagnosticAnalyzerExecutor interface.

it was added when OOP is first introduced to make sure VS.Next dll won't get loaded to VS process if OOP is not enabled.

when it is enabled by default, rather than removing the interface, implementation just moved down to feature layer to reduce code churn.

now, I am properly removing unnecessary abstraction.

* take Executor out of test MEF composition

* added IRemoteDiagnosticAnalyzerService interface

* made initial version working.

* added tests

* add tracking for inproc only analyzers

* pass in diagnostic analyzer service

* added open file performance tracking as well.

* added PII test

* dont hash analyzerId when it is reported by internal user

* added link to LOF wiki

* made blame to track open files as well.

* forgot to add return in if statement

* reduce threshold to 100ms

decide to start from lower threshold and then iterate rather than start from higher threshold

* added a way to log real time perf data in local machine with explicit option which can be used to train formula later

* addressed ivan's feedbacks

* renamed to ExpensiveAnalyzerInfo

* addressed PR feedbacks

* more renames

* addressed PR feedbacks.

renamed as much as I can find.

* listener can be null in unit test

* addressed PR feedbacks

Return FormattableString for BoundTupleExpression.Display/BoundStackAllocArrayCreation.Display and allow FormattableString in DiagnosticInfo.Arguments.

Updating nuget prerelease versions

Merge dev15.7.x to features/compiler

Check generic construction diagnostics for stackalloc to span conversions

Enable building targeting arm64 platform

Move more test projects to net461

* Fixed cases where 1:1 mapping between Roslyn and editor text buffer/snapshot are broken.

First case was where the code reused same Roslyn text snapshot to 2 different editor snapshots.
that can cause getting editor snapshot from roslyn snapshot to fail.

Second case was where same editor snapshot can give 2 different roslyn text snapshot breaking
invariant.

didn't do much cleanup except fixing those above two.

* null check. weakReference can be null.

* make sure weakReference always exist

* fixed test failures

* addressed PR feedbacks

* updated comment

Refer directly to static data when ReadOnlySpan wraps arrays of bytes.

Skip CSharpBuild.BuildWithCommandLine while failures are investigated.

Add missing resource string to VB for Interpolated String feature.

Merge pull request #23587 from MaStr11/AddParenthesisAroundConditionalExpressionInInterpolatedStringCodeFixProvider

Add parentheses around conditional expression in interpolated string code fix provider

Fix typo in Microsoft.NETCore.Compilers props file

Merge dev15.7.x to features/compiler

Multitarget our msbuild task