NFCI. With the move to the new pass manager by default, sanitize-coverage.c is now passing on ARM.

This change removes the XFAIL from the original test and duplicates the test into sanitize-coverage-old-pm.c
which uses the old pass manager and has the corresponding XFAIL.

This should fix the XPASS from this and similar runs:
http://lab.llvm.org:8011/#/builders/60/builds/1875