Add simplifier annotation on using directives generated via the Add Using fix so that generated directives are already simplified (in the case where using is generated inside a namespace declaration) without the user having to simplify manually in a subsequent step.

Note: I also added the annotation inthe corresponding VB fix for parity. However, this should be a no-op for VB since VB only supports file-level namespace imports.

Fixes #1893

Use SymReader from debugger (that supports CDI from EnC pdbs)...

This involves a couple changes:

- Fix signature of IENCSymbolReaderProvider.GetSymbolReader
- Remove all of our "fallback" SymReader creation logic and use
  ISymUnmanagedReader3 when getting custom debug info

Clean up local scopes produced by PdbToXml and update tests accordingly

Explicitly hold on to fields that can be accessed from background thread

Fix localization test failure in TestReportingUnsupportedDiagnostic. Fixes #1392  

Fixes EnC function remapping of an active statement containing await expression

Explicitly hold on to fields that can be accessed from background thread in local so that we don't run into NullReferenceException / ArgumentNullException when these end up getting cleared as part of Dispose()

Honor requested categories and spans specified by light bulb

The previous code for PDB emit was erroneously assuming that extern
alias declarataions and usings/imports for those declarations could
only occur at the top-level namespace scope.

This changes PDB emit to walk through all scopes above the use site
instead of just the top-level scope.

Fixes #1764.

Fix a crash during IL generation for an Expression Tree involving an extension Add method used within a collection initializer

1. When light bulb asks us for suggestions (i.e. in HasSuggestedActionsAsync() and GetSuggestedActions()), it also specifies the category of suggestions that it is looking for (code fixes, refactorings, anything etc.). So far, we were completely ignoring the requested categories. HasSuggestedActionsAsync() would always return true so long as we had a code fix (that is not a suppression fix) and GetSuggestedActions() would always return all types of suggestions (fixes, suppressions and refactorings) regardless of what the light bulb is asking for. This led to strange bugs where we would return refactorings even when light bulb didn't ask for them. In other cases, HasSuggestedActionsAsync() and GetSuggestedActions() would disagree for the same requested categories. This change makes things consistent so that we always honor the suggestion categories that the light bulb is requesting.

2. When computing refactorings we were completely ignoring the span specified by light bulb and only considering selection specified by user. This led to incorrect behavior in some cases - for example, on mouse hover over a squiggle, we would return the code fixes corresponding to the squiggle along with refactorings for completely unrelated portions of the code that the user may have previously selected.

Fixes #1030, #1595, #1631

Fixed parsing logic for rsp file arguments to implement speced behavior.

make persistent service not to support project k for now.

...

also change to use cached IVsHierarchy only for error list filtering due to issue with caching it on shared projects

VisualBasicCodeModelService should handle Constructor case for Function ...

In particular, it is allowed for arguments to have embedded quoted portions like

/define:Unquoted"Quoted"Unquoted"Quoted"

wich means

/define:UnquotedQuotedUnquotedQuoted

when passed on command line, and should mean exactly the same when passed in an rsp file.

The change fixes #1784

Expand LINQ expression for building auto-completion brace chars to reduce JIT time in the "open file" scenario.

VisualBasic CodeModel Service should handle Declare Function and Sub for St...

Fix DiagnosticAnalyzerExtensions.GetDiagnosticAnalyzerCategory to return DiagnosticAnalyzerCategory.SemanticDocumentAnalysis if the analyzer has semantic actions and cannot support semantic span based analysis.

Fixes #1709 

Fix #1843 : VisualBasicCodeModelService to get the function kind for Constructor had
a syntactic blunder where the case was not allowed to fall through

Fix #1839 : Visual Basic CodeModelService not handles Declare Function
and Sub for StartPoint and EndPoint.

Fix DiagnosticAnalyzerExtensions.GetDiagnosticAnalyzerCategory to return DiagnosticAnalyzerCategory.SemanticDocumentAnalysis if the analyzer has semantic actions and cannot support semantic span based analysis.

Fixes #1709

also change to use cached IVsHierarchy only for error list filtering due to issue with caching it on shared projects

Require correct null constant encoding in metadata

Currently, a bug is present in the perf machine where the compiler
server parent directory and the client parent directory differ only by
casing. Rather than try to fix this specific instance, we should remove
the reliance on .NET APIs to return the same value for the client and the
server by simply passing the pipe name to the compiler server.

This should mean that every identical instantiation of the client results
in the same pipe name and remove the logic in the server.

Document moniker look up for shared item that is a contained document

Refactoring the code a bit. Pushed the mapping of hierarchy to shared hierarchy and itemId to shareditemId into LinkedFile Utility class. So now we give a hierarchy, itemId pair and get back a sharedhierarchy, itemId pair.

Port CA1813 (Avoid Unsealed Attributes) to System.Runtime.Analyzers.

Unskip tests fixed by #662 and #679. 

show conditional element access sig-help after arbitrary expressions

the old model would only appear after an identifier name

don't assume that a constructor's parent is a TypeBlockSyntax

Fix variable capturing for VB lambdas in EE...