Locate VS InstallDir in the presence of newer runtime

This fixes getSystemRegistryString() in WindowsToolChain.cpp to
make sure that the VS version that it picks has an InstallDir.
Previously we would look for the highest version os VS and check
for InstallDir afterwards.

Patch by Yaron Keren!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192374 91177308-0d34-0410-b5e6-96231b3b80d8
ObjectiveC migrator: For 'default' and 'shared' family of
methods, infer their self's type as their result type.
// rdar://15145218


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192377 91177308-0d34-0410-b5e6-96231b3b80d8
Debug Info: update testing cases when the context field of subprogram is updated
to use DIScopeRef.

Paired commit with r192378.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192379 91177308-0d34-0410-b5e6-96231b3b80d8