An alloca which can be sunk into the extraction region may have more
than one bitcast use. Move these uses along with the alloca to prevent
use-before-def.
Testing: check-llvm, stage2 build of clang
Fixes llvm.org/PR42451.
Differential Revision: https://reviews.llvm.org/D64463
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365660 91177308-0d34-0410-b5e6-96231b3b80d8
0edfaf6dd2