* Include PDB Checksum in Debug Directory

* Xlf files

* Add more validation

* Fix tests

* Fix xplat test

* Remove data signature

This reverts commit 7dd78ae8, reversing
changes made to 449f5586.

This change drops support for .NET 4.5 and retargets to desktop
4.6 + CoreCLR. It also fixes up various analyzer warnings that
were created due to the move.

Fixes #12926

Corrects a couple of items noted in #7677

Address feedback from Tom: Ensure that we unsubscribe the exception handler registered with LocalizableString when the analyzer reference is disposed by the host. This will prevent statically instantiated LocalizableString instances from leaking the handler, and hence the analyzer instance.
We now have a public OnException event on the LocalizableString, which is invoked on exceptions. AnalyzerManager registers host's exception handler when populating descriptor cache per analyzer and unregisters this handler when host is disposing the analyzer.

Revert "Address review feedback from Heejae: add DiagnosticDescriptor.WithOnException to create a new descriptor with hooked up exception handler for reporting exception diagnostics from LocalizableStrings, instead of mutating fields of LocalizableString implementations."

This reverts commit 4e120580.

Address review feedback from Heejae: add DiagnosticDescriptor.WithOnException to create a new descriptor with hooked up exception handler for reporting exception diagnostics from LocalizableStrings, instead of mutating fields of LocalizableString implementations.

This is the final change in the series of changes I have been making to ensure that compiler and IDE are completely hardened against exceptions from analyzers.

This change makes the DiagnosticDescriptor completely exception safe. Currently, DiagnosticDescriptor has lazily evaluated LocalizableString fields for Title, MessageFormat and Description. These have public extension points at ToString, Equals and GetHashCode methods, all of which can throw. These callbacks have now been wrapped within a try-catch for our LocalizableResourceString implementation of LocalizableString. For custom user implementations of LocalizableString (which should hopefully be rare), we wrap these within an ExceptionSafeLocalizableString which calls into the inner localizable string wrapped within a try-catch. All this is done within the DiagnosticDescriptor constructor, none of the clients have to explicitly handle the exception at use sites.

1) Make LocalizableString implement IEquatable<LocalizableString> to ensure Diagnostic equality works as expected for Descriptor based diagnostics.
2) Additionally, also refactor code a bit more to move register/unregister code for analyzer exception diagnostics down to the core AnalyzerDriverHelper.
3) Fix test failures.

This change introduces an overload of the LocalizableResourceString constructor which does not take any formatting arguments.

Memspect reported over 3,000 instances of zero-length string arrays being created for constructing LocalizableResourceString.

Microsoft.CodeAnalysis.CSharp.dll!Microsoft.CodeAnalysis.CSharp.ErrorFacts.GetTitle
Microsoft.CodeAnalysis.CSharp.dll!Microsoft.CodeAnalysis.CSharp.ErrorFacts.GetDescription
Microsoft.CodeAnalysis.CSharp.dll!Microsoft.CodeAnalysis.CSharp.ErrorFacts.GetMessageFormat (changeset 1406198)

These were accidentally changed to UTF-16LE during a recent scripted change.  This went unnoticed because the encoding change didn't register in CodeFlow (indeed if you view a shelve of this change in CodeFlow it will report no changes).  UTF-16 does not work well with Git as it is often interpreted as a binary file.  Moving back to UTF-8 so our GitHub experience works well for customers.

closes #66 (changeset 1403787)

Background:

As discussed in the dev team all hands all code under the GitHub dotnet foundation is using a single process for contribution, API review, infrastructure and coding style. The idea is to present a unified view to our customer and give them a single story for contributing to any project under the dotnet foundation.

https://github.com/dotnet/corefx/wiki/Contributing#c-coding-style

The coding style transition is automated using a Roslyn based rewrite tool:

https://github.com/dotnet/codeformatter

This will be applied in stages across our developer tree. Right now the focus is on the Open directory as this is what is being presented on github. Code owners will be contacted before the transition happens.

Note: this is a soft style requirement. There are no build errors that come from this change.
 (changeset 1403394)

Fix for bug 1086767: Title and Descriptor fields in DiagnosticDescriptor cannot take arguments if they want to be localized

Add params array parameter for format arguments to LocalizableResourceString constructor. (changeset 1378542)

1) Implement diagnostic analyzers which register syntax tree action (syntax diagnostics), semantic model action (semantic diagnostics) and compilation end action (declaration diagnostics with non-source location)

2) Add C# and VB code analysis assemblies as analyzer assets to VisualStudioComponents VSIX manifest file.

3) Remove special casing of CompilerDiagnosticsProvider in the IDE diagnostic service, its just a regular VSIX based analyzer now.

4) Add WellKnownDiagnosticTags.NotConfigurable tag to all compiler errors and ensure that we don't suppress/filter diagnostics or analyzers with this tag. (changeset 1377682)

Primary intent here is to try and avoid breaking changes, while also keeping the usage for Diagnostic authors as simple as possible. On these lines, the primary changes here are:

1) Add an abstract LocalizableString type to represent strings that could be possibly localized. Provide an implementation of this type for resource strings from ResourceManager: LocalizableResourceString.

2) Change type of DiagnosticDescriptor's properties for Title, Description and MessageFormat to LocalizableString and change Diagnostic to implement IFormattable.

3) Expose DiagnosticDescriptor from Diagnostic: Change SimpleDiagnostic (used for all publically created diagnostics, except compiler diagnostics) to store the DiagnosticDescriptor instead of it's individual fields such as id, description, etc. In a subsequent change, we will move the compiler diagnostics also to be descriptor based.

See the change to CA1001 and CA1708 DiagnsoticAnalyzers in this change to see how the client can pass in the localizable strings. (changeset 1371578)