Revert "Avoid global contstructors and place static variables

inside classes as static local variables and remove the static
ivars. Subclasses should use the accessor functions."

This change moved global statics to function local statics, but
forgot to make the locals static in the function, breaking all
platforms.  Furthermore, MSVC doesn't support thread-safe function
local statics, so any use of a function local static on non
primitive types is undefined behavior on MSVC.

Reverting due to the fact that it's broken on all platforms, but
would like to have a discussion about the thread-safety issue
before it goes back in.

llvm-svn: 216123