exposed with a fastcc problem (breaking pcompress2 on x86 with -enable-x86-fastcc).
When reloading a reused reg, make sure to invalidate the reloaded reg, and
check to see if there are any other pending uses of the same register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26369 91177308-0d34-0410-b5e6-96231b3b80d8