Add function DominatorTree::getDescendants(). 

  As its name suggests, this function will return all basic blocks
dominated by a given block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191014 91177308-0d34-0410-b5e6-96231b3b80d8
msbuild: Set _MSC_VER to match the CRT we're using

Various Windows SDK headers use _MSC_VER values to figure out what
version of the VC++ headers they're using, in particular for SAL macros.

Patch by Paul Hampson!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191015 91177308-0d34-0410-b5e6-96231b3b80d8