[ARM] In dynamic-no-pic mode, ARM's post-RA pseudo expansion was incorrectly
expanding pseudo LOAD_STATCK_GUARD using instructions that are normally used
in pic mode. This patch fixes the bug.

<rdar://problem/17886592>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214614 91177308-0d34-0410-b5e6-96231b3b80d8