Merge from master

made roslyn to use new GetContentLocation API from extension manager

added column filter to suppression column so that it doesnt count in …

turn off low latency mode when we hit low memory situation.

Merge pull request #8655 from jasonmalinowski/remove-silly-resolveassemblywarnorerrorOntargetarchitecturemismatch

Remove useless ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch…

This appears to have exposed a bug in the compiler.  Disable checking for now.

see #8739 for more details.

IOperation conditional access expression API change

Renamed more VB private members that implement interface members using the convention of InterfaceName_MemberName.

the low latency mode is introduced in the early days of Roslyn to make sure we always hit 50ms typing responsive time in our own perf lab typing test.

basically that mode prevent GC to get into most expensvie blocking gen 2 collection. which is nice most of time, but when we are under low memory sitatuion, not doing blocking gen 2 also means we don't do compact.

and that I believe can cause us to be in a sitatuion such as https://github.com/dotnet/roslyn/issues/6802

this basically let us turn that optimization off sacrifying keystroke responsiveness time to time to have more memory available to us.

this mode is supposed to force blocking gen 2 collection when GC detects its own low memory condition, but that seems not consider when there is some free memory left but all those are fregmented.

 Localize display properties for analyzers in solution explorer

Renamed private members that implement interface members using the convention of InterfaceName_MemberName.

Conflicts:
	src/Compilers/CSharp/Test/Semantic/Diagnostics/OperationAnalyzerTests.cs
	src/Compilers/Core/CodeAnalysisTest/Diagnostics/OperationTestAnalyzer.cs
	src/Compilers/VisualBasic/Test/Semantic/Diagnostics/OperationAnalyzerTests.vb

Simplify IAssemblyReference

Fix IBinaryOperatorExpression, IUnaryOperatorExpression and IIncrementExpression

In cases where it is sopposed to represent error state.

1. Add `invalid` value to `SimpleUnaryOperationKind`, `UnaryOperandKind`, `UnaryOperationKind`,
   `SimpleBinaryOperationKind`, `BinaryOperandsKind` and `BinaryOperationKind`.
2. Make BinaryOperationKind/UnaryOperationKind property return Invalid kind instead of throwing
   exception when handling code with errors.

Revert "Merge pull request #8641 from CyrusNajmabadi/addUsingInteractive"

This reverts commit 18d27544, reversing
changes made to 5925aaef.

The change being reverted was hte one to speed up add-using in the interactive
window. However, i'm concerned about potential perf problems this may cause in
the mainline add-using case. I'm reverting this for now until i can come up
with a fix i think is suitable for both.

Merge from branch 'master' to 'stabilization'

address more PR feedback.

Conflicts:
	src/Compilers/Core/CodeAnalysisTest/Diagnostics/OperationTestAnalyzer.cs

IOperation API review

Moving the Glyph enum back to the 'Features' dll.

Ensure custom modifiers are copied for types of overriding properties and events even in the case of dynamic/object mismatch.

Improve add-using perf in interactive window.

Fixes #8637

Correctly localize the "Failure" and "Warning" strings