[clang] [flang][driver] support -dumpversion and -dumpmachine (PR #68896)

[Yuanfang Chen via cfe-commits]

yuanfang-chen wrote:

> Could this be implemented without any updates to Clang (beyond Options.td)?

The options could work by changing options.td only. However,  `CLANG_VERSION_STRING` and `FLANG_VERSION_STRING` could be different. This is to handle that.

https://github.com/llvm/llvm-project/pull/68896