Align stubs for external and common global variables to pointer size.

This patch fixes PR36885: clang++ generates unaligned stub symbol
holding a pointer.

Patch by Rahul Chaudhry!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329030 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed