[OpenMP] Fixed Bug 49356

Bug 49356 (https://bugs.llvm.org/show_bug.cgi?id=49356) reports crash in
the test case `tasking/bug_taskwait_detach.cpp`, which is caused by the wrong
function declaration. `gtid` in `__kmpc_omp_task` should be `kmp_int32`.

Reviewed By: AndreyChurbanov

Differential Revision: https://reviews.llvm.org/D102584