Fixes #4097.

Fix GetDiagnostics(span) to return all diagnostics intersecting the span, rather than just the diagnostics contained within the span.

Fixes #3892 and #4559

Updating System.Reflection.Metadata to 1.1.0-alpha-0015 and System.Collections.Immutable to 1.1.37.0

Revert "Updating System.Reflection.Metadata to 1.1.0-alpha-0015 and System.Collections.Immutable to 1.1.37.0"

This reverts commit d78dbb97.

Updating System.Reflection.Metadata to 1.1.0-alpha-0015 and System.Collections.Immutable to 1.1.37.0

Reverting System.Collections.Immutable back to 1.1.36 until we can upgrade System.Reflection.Metadata simultaneously

Updating Microsoft.DiaSymReader to v1.0.6, Microsoft.DiaSymReader.Native to v1.2.0, and System.Collections.Immutable to v1.1.37

Fixes #5725.

Fixes #5631.

Gracefully handle format exception from Diagnostic.GetMessage() when the analyzer reports a diagnostic with incorrect format arguments.

Fixes #4589

1. Fixes #5463: VB field and property declarations don't include the "AsClauseSyntax" node in the node's "Initializer" field, which caused us to miss executing the syntax node actions for AsNewClauseSyntax nodes within code blocks. Now we explicitly account for these initializer nodes.

2. Fixes #4745: C# namespace symbols defined by a qualified name such as "X.Y.Z" within "namespace X.Y.Z {}", all have the same declaring syntax reference. So we need to ensure that we don't make duplicate syntax node callbacks for such namespace declaration nodes.

Avoid rebinding references bound to explicitly specified definitions, even if a better version is available after resolution

Disabling flaky tests from http://dotnet-ci.cloudapp.net/job/roslyn-internal_master_win_rel_unit32/7/

Fixes #5516

Fixes #5395.

Adjusted Binder, Optimizer, Flow Analysis, code generator and majority of bound tree visitors to not use recursion to handle binary expressions nested on the left side of another binary expression.
Adjusted majority of bound tree visitors to detect that stack overflow is about to happen while an expression is being traversed and report a diagnostic pointing to the expression at fault instead of crashing compiler.

(fixes DevDiv 790235)

Naming the execution scripts 'csc.sh' and 'vbc.sh' is counter to the
convention of not using any extension on *nix executables. While the
scripts are not strictly executable programs, they are meant to be
transparent shims around the actual execution of the compilers on *nix