Enable support for vector sext and trunc:
Limit the folding of any_ext and sext  into the load operation to scalars.
Limit the active-bits trunc optimization to scalars.
Document vector trunc and vector sext in LangRef.

Similar to commit 126080 (for enabling zext).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126424 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed