Fortran: fix functions with entry and pointer/allocatable result [PR104312]

Fortran: fix functions with entry and pointer/allocatable result [PR104312]

gcc/fortran/ChangeLog:

	PR fortran/104312
	* resolve.cc (resolve_entries): Handle functions with ENTRY and
	ALLOCATABLE results.
	* trans-expr.cc (gfc_conv_procedure_call): Functions with a result
	with the POINTER or ALLOCATABLE attribute shall not get any special
	treatment with -ff2c, as they cannot be written in Fortran 77.
	* trans-types.cc (gfc_return_by_reference): Likewise.
	(gfc_get_function_type): Likewise.

gcc/testsuite/ChangeLog:

	PR fortran/104312
	* gfortran.dg/entry_26.f90: New test.
	* gfortran.dg/entry_27.f90: New test.