Change objectsize intrinsic to accept different address spaces.

Bitcasting everything to i8* won't work. Autoupgrade the old
intrinsic declarations to use the new mangling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192117 91177308-0d34-0410-b5e6-96231b3b80d8