[OpenMP] [Flang] Resolved Issue llvm#76121: Implemented Check for Unhandled...

[OpenMP] [Flang] Resolved Issue llvm#76121: Implemented Check for Unhandled Arguments in __kmpc_fork_call_if (#82221)

Root cause: Segmentation fault is caused by null pointer dereference
inside the __kmpc_fork_call_if function at
https://github.com/llvm/llvm-project/blob/main/openmp/runtime/src/z_Linux_asm.S#L1186


. __kmpc_fork_call_if is missing case to handle argc=0 .

Fix: Added a check inside the __kmp_invoke_microtask function to handle
the case when argc is 0.

---------

Co-authored-by: Singh <chasingh@amd.com>