flang: add an option to ignore -mmacos-version-min

[georgthegreat]

We are porting our clang-only based build system to support flang-new.

I have run into an issue with -mmacos-version-min option which is not supported by flang-new.
As this option looks like a mandatory part of a target triplet, we set both up together and splitting them looks nasty.

While flang itself does not support dynamic / static macOS version check, maybe we can simply ignore this option for now?

[georgthegreat]

@banach-space, it would be nice if you could look on this too.

[banach-space]

Thanks for sending this!

@banach-space, it would be nice if you could look on this too.

I don't work on Flang these days. I tagged @tarunprabh, who's now the driver maintainer.

[kiranchandramohan]

Support for this option was added in #143508, #147273 by @tblah and @DavidTruby.

[georgthegreat]

Thanks! We will update to flang-21 then.

[llvmbot]

@llvm/issue-subscribers-flang-driver

Author: Yuriy Chernyshov (georgthegreat)

We are porting our clang-only based build system to support flang-new.

I have run into an issue with -mmacos-version-min option which is not supported by flang-new.
As this option looks like a mandatory part of a target triplet, we set both up together and splitting them looks nasty.

While flang itself does not support dynamic / static macOS version check, maybe we can simply ignore this option for now?