[x86] Refresh the checks of a number of tests using

update_llc_test_checks.py.

The exact format of the checks has changed over time. This includes
different indenting rules, new shuffle comments that have been added,
and more operand hiding behind regular expressions.

No functional change to the tests are expected here, but this will make
subsequent patches have a clean diff as they change shuffle lowering.

llvm-svn: 228097