Fortran: Reject semicolon after namelist name.

	PR fortran/109662

libgfortran/ChangeLog:

	* io/list_read.c: Add check for a semicolon after a namelist
	name in read input. Issue a runtime error message.

gcc/testsuite/ChangeLog:

	* gfortran.dg/pr109662-a.f90: New test.