[Driver] -###: exit with code 1 if hasErrorOccurred

The exit code for -### is inconsistent. Unrecognized options lead to
exit code 1, as expected. However, most others errors (including invalid
option value) lead to exit code 0, differing from GCC and most utilities.

This is a longstanding quirk of -###, and we didn't fix it because many
driver tests need adjustment.

Change -### to be similar to -fdriver-only -v and exit with code 1.

This requires fixing many driver tests, but the end result gives us
stronger tests.

* Existing `RUN: %clang -### ...` tests usually don't use `CHECK-NOT: error:` or `--implicit-check-not=error:`.
  If a change introduces an error, such a change usually cannot be detected.
* Many folks contributing new tests don't know `-fdriver-only -v`.
  To test no driver error/warning for new tests, they can use the familiar `-### -Werror`
  instead of `-fdriver-only -v -Werror`.

Reviewed By: jhuber6, yaxunl, dblaikie

Differential Revision: https://reviews.llvm.org/D156363

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