Broken support of OpenMP with GFortran

[jbloino]

Xmake Version

2.9.5

Operating System Version and Architecture

macOS Sonoma 14.6.1, Linux debian testing kernel 6.9.10

Describe Bug

gfortran fails to link the OpenMP library at the final compilation stage, with all references to OpenMP primitives unresolved.
This problem was confirmed on mac OS X arm64 and Linux AMD 64.

Expected Behavior

The compilation should work

Project Configuration

xmake.lua

add_rules("mode.debug", "mode.release")
add_requires("openmp")

target("test_omp")
    set_kind("binary")
    add_packages("openmp")
    add_files("test_openmp.f90")

test_openmp.f90

program test_openmp
    integer, external :: omp_get_num_threads

    !$omp parallel
    print '("Number of threads: ",i0)', omp_get_num_threads()
    !$omp end parallel

end program test_openmp

Additional Information and Error Logs

It seems that the problem is in the use of result.fcldflags = "-fopenmp" on l.77.
Replacing it with result.ldflags = "-fopenmp" fixes the problem (the "shared" case was not tested).