…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)
  ...