Address failing Fujitsu test suite cases that were broken by the patch
to defer the handling of !$ lines in -fopenmp vs. normal compilation to
actual compilation rather than processing them immediately in -E mode.
Tested on the samples in the bug report as well as all of the Fujitsu
tests that I could find that use !$ lines.
Fixes https://github.com/llvm/llvm-project/issues/136845.
58535e81dd