[X86] Re-generate abi-isel.ll checks with update_llc_test_checks.py

These tests were clearly auto-generated when they were converted to
FileCheck back in r80019 (2009), but we didn't have a fancy script to
keep them up to date then. I've reviewed the diff, and we should be
generating the exact same code sequences we used to.

After this, I plan to commit a change that changes our output slightly,
but in a way that is still correct. It will generate a large diff, and I
want it to be clearly correct, so I am regenerating these checks in
preparation for that.

llvm-svn: 338928