Fortran: IS_CONTIGUOUS and pointers to non-contiguous targets [PR114023]

Fortran: IS_CONTIGUOUS and pointers to non-contiguous targets [PR114023]

	PR fortran/114023

gcc/fortran/ChangeLog:

	* trans-expr.cc (gfc_trans_pointer_assignment): Always set dtype
	when remapping a pointer.  For unlimited polymorphic LHS use
	elem_len from RHS.
	* trans-intrinsic.cc (gfc_conv_is_contiguous_expr): Extend inline
	generated code for IS_CONTIGUOUS for pointer arguments to detect
	when span differs from the element size.

gcc/testsuite/ChangeLog:

	* gfortran.dg/is_contiguous_5.f90: New test.

(cherry picked from commit 3f8b6373f48af0eabbc2efe04df8f6856add3111)