Address CR feedback (changeset 1342758)
Split "Simplify type names" diagnostic into 3 sub-categories with different diagnostic IDs:
(a) Simplify type names (name syntax)
(b) Simplify member access (simple member access expression)
(c) Simplify this or Me qualification (this or me expression)

Fix all occurrences executed on these diagnostics will do the following respectively:
(a) Simplify type names: Simplify all instances of given type name
(b) Simplify member access: Simplify all instances of given member access
(c) Simplify this or Me qualification: Simplify all instances of this/Me qualification

Bug 1033012 ([Pending design] Add FixAllProvider API support for flavored nested actions with different interpretations) would enable different interpretations of "fix all" for these diagnostics post-preview.
 (changeset 1342868)
Move FixAll related files into a sub-folder. (changeset 1342870)
CR.Feedback on TaskFactoryExtensions

removed one that doesn't take cancellationtoken to make it more explicit. (changeset 1342960)
Change compilers to not use references to script runtime classes for submission code gen.
 (changeset 1343137)
Test for bug 1036339: GetDiagnostics fails with NullReferenceException for optional parameter in security attribute (changeset 1343346)
Fix a bad codegen when switch header is emitted on an optimized local.

The code that was supposed to prevent that situation from happening was not handling all cases.
 (changeset 1343365)
Test for bug 1036356: Assert fails at Microsoft.CodeAnalysis.CSharp.LocalRewriter.MakeConversion for [DefaultParameterValue(DayOfWeek.Monday)] (changeset 1343368)
Remove Primary Constructors feature for now. (changeset 1343454)
CR feedback for 1331612 (changeset 1343547)
Prototype for string interpolation in C# (changeset 1343548)
Add support for SHA256 PDB checksums. (changeset 1343620)
removed previously added diagnostic code to pin piont race in workspace. it turns out race is not in workspace but in language services. added new diagnostic code in language services and removed one in workspace. (changeset 1343621)
Fix typos (changeset 1344025)
The Roslyn code base was terminating on a stack overflow in places where the native compiler would issue a simple error. This is acceptable behavior for the command line compiler but troublesome for the IDE where it was causing Visual Studio to terminate on bad code. Simply pasting certain samples caused the IDE to vanish with data loss.

This change uses RuntimeHelpers.EnsureSufficientStackSpace to help guard against this problem. This function will terminate with a recoverable exception if the CLR determines insufficient stack space is available for an average .Net function to execute.

At the moment this function isn't available in the PCL hence reflection is needed. Once it becomes available the reflection will be removed and the hepler will be accessed directly. (changeset 1344040)
Fix some O(n^2) codepaths to allow faster MetadataAsSource processing of large enums.

AbstractCodeGenerationService.AddMembers was using an O(n^2) algorithm to insert new members.  This change allows bulk inserting members if the AutoInsertionLocation flag is false.  For now, metadata as source only sets AutoInsertionLocation to false for enum symbols which can commonly have thousands of members.

SeparatedSyntaxList.InsertRange was also calling Insert for each node.  It now adds the nodes in a single step. (changeset 1344073)
Replaces usages of NoLocationVariable with simple synthesized variable or with TypeSubstitutedLocalSymbol.
Remove some unnecessary differences between implementations of LocalSymbol in VB and C#. (changeset 1344093)
Provide a reasonable Display name for invalid analyzer references.

Currently, if an AnalyzerFileReference cannot read the assembly to determine the assembly name (because the file is missing, or inaccessible, or isn't an assembly, etc.) we simply return base.Display. This is silly, as AnalyzerReference.Display simply returns null.

Instead, we should simply return the file name. (changeset 1344129)
Fix bug with missing recursive lowering of string interpolation insert (changeset 1344138)
narrowed down a bit more to see which part is having a problem.

removed previous diagnostic code and added new one which most likely tell us what went wrong. (changeset 1344144)