Change TargetFrameworkVersion to 4.5.2 for Workspaces layer and to 4.6 for Visual Studio pieces.

Rename emitOptions and compOptions parameters of test helpers

Emit tokens for TypeSpecs in imports

Add AssemblyRefs and TypeRefs to assemblies and types referenced by imports

Normally, the build client for the compiler server looks for the server
in the same directory as itself (the running executable), however when
the client is inside the build task, the task may be GAC'd and thus the
server may be nowhere near by.

If so, we should fallback to the location MSBuild found the client exe
in (usually the default MSBuild directory), and otherwise give up if
we aren't given a fallback path.

Add AssemblyRefs and TypeRefs to assemblies and types referenced by imports, even if they are not referenced otherwise

Code Cleanup should remove spaces between Colon and Equals

Split ReferenceIndexer.cs into 3 files - one for each declared class

Fixes #1604.
Closes #1605.

Fill in Image Debug Directory 'manually' instead of relying on what SymWriter gives us

This API doesn't exist in CoreFx.  It was used in EncodedStringText as
the last ditch effort for string decoding.  Switched to explicitly use
codepage 1252 as the last ditch encoding effort.

closes #1623

This function relied on CultureInfo which is not a supported CoreFx API.
Moved it out to the Desktop layers where it was actually used.

Remove uses of

- XmlResolver
- GetType(string, bool) for GetType(string, bool, bool)
- Remove Assembly.GetAssemblyName

Remove private copy of IComWrapper and use the one from the VSSDK

This implementation changes the compiler server named pipe to use
the SHA1 hash of the compiler exe directory as the named pipe name.
The client then attempts to connect to the pipe with this name and,
if it is unable, starts the server, which creates and connects to
a pipe of said name. If all else fails, continue with fallback
compilation as usual.

change the way build and live diagnostics are merged

previously we made system to prefer live diagnostic over build diagnostic.
also when we merge those two, we used very detail info to find out build and live diagnostics are same or not.

but the issue was diagnostics from build didn't have all information live one has, also diagnostics from build is static
when live one is changing as user type in IDE. which lead to race where build diagnostic might be already out-dated on arrival.

new system is that we prefer diagnostic from build over live. and don't distinguish them by detail info but whether live can produce
same diagnostics build produced. as user change file, we will replace build diagnostics in affected files to live diagnostics.

this should remove chance where build diagnostic got stuck in the system until next build. and as user change files, live diagnostic
over take build diagnostics.

don't do partial analysis on out of sync range

Blind aggregator light-up

Replace AsyncSemaphore with SemaphoreSlim. AsyncSemaphore is no longer
necessary since we moved to 4.5.2

Eliminate the blob of reflection used to get the PointerOffset field.
Now we're using 4.5.2, we can get at the offset directly.

Fill in Image Debug Directory 'manually' instead of relying on what SymWriter gives us, other than the GUID it generates. Enables generating debug directory when emitting Portable PDBs.

changes around solution crawler.

first, made solution crawler options to show up in Roslyn/Option pane to make experiement easier.
second, tweaked the way higher/normal/low priority processor interact each other.
last, made solution crawler to pick next project to process a bit smarter.

misc.
fixed an issue where lazyLogmessage didn't clear cached message correctly
changed etw logging default to not log at all

Touch file

Update DiaSymReader to v1.0.4

Add validation of PE debug directory to PDB tests