Memory: Do process and 1st thread tear down.

Addresses #928, #389, and 1st item in #976. Overlaps #916.

This had been dropped, when moving away from the old Win32 DLL model.

Issue: per-thread tear down for other threads.

OGLCompilersDLL/InitializeDll.cpp

@@ -148,8 +148,6 @@ bool DetachProcess()
     if (ThreadInitializeIndex == OS_INVALID_TLS_INDEX)
         return true;
 
-    ShFinalize();
-
     success = DetachThread();
 
     FreePoolIndex();