…n body

…c type

# Conflicts:
#	src/Features/CSharp/Portable/CSharpFeaturesResources.resx

* Fix code style issues in tests
* Fix handling of multiple containing generic types, and add a test
* Fix handling of unrelated type hierarchies with no shared type parameters
* Add a skipped test and bug for type hierarchies with shared type parameters (see dotnet#27950)

Fixes edge cases where variable identifier name is reused in the initializer as first part of member access qualification.
Example: SomeEnum SomeEnum = SomeEnum.EnumVal1

Fixes dotnet#26894

…orm.

Additionally summary documentation and identifier names have been adjusted to swap
'parent loop/switch' with 'corresponding loop/switch'.

Update 'use block body' to be better understand async methods.

…/compiler

Merge master to features/compiler

…, SelectMany and Where invocations)

Adds one of the refactorings mentioned in dotnet#8953

```
//
// INPUT:
//   foreach (var n1 in c1)
//      foreach (var n2 in c2)
//          if (n1 > n2)
//              yield return n1 + n2;
//
// OUTPUT:
//   c1.SelectMany(n1 => c2.Where(n2 => n1 > n2).Select(n2 => n1 + n2))
//
```

… to the refout docs (dotnet#29404)

Update unix contributing docs

Instructions can be found in the README file under src/Tools/CompilerBenchmarks.

Fixes dotnet#29416

Add refactoring to convert foreach loop into linq invocations (Select…

Restore the machinery for enabling language features by feature flags

Add new DiagnosticAnalyzer API for Symbol Start/End analysis

…features/compiler

# Conflicts:
#	src/Compilers/Core/Portable/CodeAnalysisResources.resx
#	src/Compilers/Core/Portable/PublicAPI.Unshipped.txt

…/compiler

Merge master to features/compiler

…atures/compiler

* dotnet/features/compiler: (183 commits)
  Document dotnet#13686 (dotnet#29416)
  Fix xml doc-comment resolution warnings
  PR feedback
  Add a perf benchmark for the compiler Emit phase (dotnet#29323)
  PR feedback
  Add documentation for the ProduceOnlyReferenceAssembly msbuild option to the refout docs (dotnet#29404)
  PR feedback
  Address PR feedback
  Expose refonly as an msbuild property (dotnet#29352)
  Add refactoring to convert foreach loop into linq invocations (Select, SelectMany and Where invocations)
  disable bad test
  Fix build error
  Restore the machinery for enabling language features by feature flags
  Assert message should sort diagnostics when possible (dotnet#29151)
  Update unix contributing docs
  Added Newtonsoft.Json to exclusion list
  Fix generation of compiler binding redirects (dotnet#29331)
  fixing hintspan size when Sub has attributes (dotnet#29115)
  Use Microsoft.SymbolUploader build task for symbol publishing (dotnet#29247)
  Remove default handling for bound nodes in (CS/VB)OperstionFactory.CreateInternal. (dotnet#29258)
  ...