Fixes a small annoyance where generated files have a format which does
not agree with the one checked during `code-formatter` in CI.
For example `libcxx-generate-files` updates (among possibly others) the
`*.version.compile.pass.cpp` files. Previously these files contained an
extra newline which would fail the code format check. If you update that
file manually to remove just that extra trailing newline, then
`check-generated-output` will fail due to the file's contents differing
from what's expected.
Contains a number of changes: one actual change to the py script, and
lots of resulting whitespace changes.
My process for this was:
* Update `generate_feature_test_macro_components`: just remove an extra
newline which causes the code-format step to fail
* Run `$NINJA libcxx-generate-files` to rebuild all these
`.version.pass.cpp`'s
* Watch this PR's CI run to ensure things pass (i.e. this didn't break
things worse)