Fortran: Fix testsuite regressions after r15-5897 [PR116261/PR117901]

Fortran: Fix testsuite regressions after r15-5897 [PR116261/PR117901]

2024-12-09  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/116261
	* trans-array.cc (gfc_array_init_size): New arg 'explicit_ts',
	to suppress the use of the expr3 element size in the descriptor
	dtype.
	(gfc_array_allocate): New arg 'explicit_ts', used in call to
	gfc_array_init_size.
	* trans-array.h : Modify prototype for gfc_array_allocate for new
	bool argument.
	* trans-stmt.cc (gfc_trans_allocate): Set new argument if the
	typespec is explicit.

gcc/testsuite/
	PR fortran/117901
	* gfortran.dg/class_transformational_1.f90: Temporary fix for
	ICE with some compile options by setting dummy arg of
	'unlimited rebar' to be allocatable.