Fortran: error recovery in frontend optimization [PR103715]

gcc/fortran/ChangeLog:

	PR fortran/103715
	* frontend-passes.cc (check_externals_expr): Prevent invalid read
	in case of mismatch of external subroutine with function.

gcc/testsuite/ChangeLog:

	PR fortran/103715
	* gfortran.dg/pr103715.f90: New test.

(cherry picked from commit 3be2b8f475f22c531d6cef1b041c0573b3ea5133)
2 files changed