[Fortran][OpenMP] flang-new: error: cannot find -lomp: No such file or directory

flang-new compiler fails to execute code with OpenMP directives. gfortran and ifx compilers seem to access libomp without any problem.

[godbolt link](https://godbolt.org/z/GPG5TT4nd)
> /usr/bin/ld: cannot find -lomp: No such file or directory
flang-new: error: linker command failed with exit code 1 (use -v to see invocation)

Start by reproducing the OpenMP failure using the linked Godbolt example and the flang-new compiler setup in this infrastructure repository. Trace why the linker cannot locate libomp, then verify that the example links and runs successfully with flang-new, as it does with gfortran and ifx.

Written by the indexing model from the issue text.