[llvm] [flang-rt] Added FLANG_RT_QUADMATH_INCLUDE_DIR option. (PR #130378)

[Slava Zakharin via llvm-commits]

vzakhari wrote:

> If the issue is that the parameter is not forwarded to the runtimes build, that's what `-DRUNTIMES_CMAKE_ARGS="-DCMAKE_CXX_FLANGS=..."` is for.

I tried exactly `-DRUNTIMES_CMAKE_ARGS="-DCMAKE_CXX_FLANGS=..."` method, but it did not work for some reason.  Let me try it again.

https://github.com/llvm/llvm-project/pull/130378