PR fortran/96711 - ICE with NINT() for integer(16) result

PR fortran/96711 - ICE with NINT() for integer(16) result

When rounding a real to the nearest integer, temporarily convert the real
argument to a longer real kind when the result is of type/kind integer(16).

gcc/fortran/ChangeLog:

	* trans-intrinsic.c (build_round_expr): Use temporary with
	appropriate kind for conversion before rounding to nearest
	integer when the result precision is 128 bits.

gcc/testsuite/ChangeLog:

	* gfortran.dg/pr96711.f90: New test.