Rename some variables to match the style guide.

I am about to patch this code, and this makes the diff far more readable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189982 91177308-0d34-0410-b5e6-96231b3b80d8
Change swift/vldm test case to be less dependent on allocation order

'Force' values in registers using the calling convention. Now, we only depend on
the calling convention and that the allocator performs copy coalescing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189985 91177308-0d34-0410-b5e6-96231b3b80d8