Until now we've been maintaining 2 test directories for Flang's drivers:
* test/Driver for `f18` (the current driver)
* test/Flang-Driver for `flang-new` (the new driver)
As we have started sharing tests between the drivers, this separation is
no longer required. This patch merges the two test directories. As
suggested in the review, moving forward we'll avoid having tests
specifically for the old driver.
A few notable changes:
* Driver/version-test.f90 and Driver/no-files.f90 are deleted. The
versions for the new driver are more robust, but tricky to share.
* Driver/write-module.f90 is deleted in favour of
Flang-Driver/write-module.f90 (see https://reviews.llvm.org/D97197
for more context)
Differential Revision: https://reviews.llvm.org/D98257
Add -J to the f18 driver for compatibility with gfortran.
Add -module-dir for compatibility with the new flang driver.
They both set the output directory for .mod files and add the
directory to the search list. -module still only does the former.
Clean up the new driver test to match.
Differential Revision: https://reviews.llvm.org/D97164
