Follow-up to D128763.
flang-new-driver
After merging https://reviews.llvm.org/D105811, `flang-new-driver` is no longer required. Differential Revision: https://reviews.llvm.org/D107990
Update test names as per Flang's coding style guide [1]: ``` File names should use dashes, not underscores. ``` [1] https://github.com/llvm/llvm-project/blob/main/flang/docs/C%2B%2Bstyle.md#files