[UpdateTestChecks] Default --x86_scrub_rip to False

True is a bad default: the useful symbol names and `@GOTPCREL` are scrubbed.

Change the default and add global variable tests to x86-basic.ll
(renamed from x86_function_name.ll since we now also test variables).
I updated some tests to show the differences.

Updated LCPI regex to include Darwin style `LCPI_[0-9]+_[0-9]+` (no
leading dot).

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D102588