Update the preprocessor regression tests to use the new driver if the new driver is built (FLANG_BUILD_NEW_DRIVER=On), otherwise the tests will still run using f18.
Summary of changes:
- Introduce %flang to the regression tests, which points to the new driver if it is built or otherwise points to f18
- Update all tests in flang/test/Preprocessing/ to use %flang
Differential Revision: https://reviews.llvm.org/D94805
This adds a test for D85862 to ensure that preprocessor definitions
passed on command lines don't regress in future.
Reviewed By: tskeith
Differential Revision: https://reviews.llvm.org/D85967
Faris Rehman