Fortran: Fix some bugs in associate [PR87477]

Fortran: Fix some bugs in associate [PR87477]

2023-06-21  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/87477
	PR fortran/88688
	PR fortran/94380
	PR fortran/107900
	PR fortran/110224
	* decl.cc (char_len_param_value): Fix memory leak.
	(resolve_block_construct): Remove unnecessary static decls.
	* expr.cc (gfc_is_ptr_fcn): New function.
	(gfc_check_vardef_context): Use it to permit pointer function
	result selectors to be used for associate names in variable
	definition context.
	* gfortran.h: Prototype for gfc_is_ptr_fcn.
	* match.cc (build_associate_name): New function.
	(gfc_match_select_type): Use the new function to replace inline
	version and to build a new associate name for the case where
	the supplied associate name is already used for that purpose.
	* resolve.cc (resolve_assoc_var): Call gfc_is_ptr_fcn to allow
	associate names with pointer function targets to be used in
	variable definition context.
	* trans-decl.cc (gfc_get_symbol_decl): Unlimited polymorphic
	variables need deferred initialisation of the vptr.
	(gfc_trans_deferred_vars): Do the vptr initialisation.
	* trans-stmt.cc (trans_associate_var): Ensure that a pointer
	associate name points to the target of the selector and not
	the selector itself.

gcc/testsuite/
	PR fortran/87477
	PR fortran/107900
	* gfortran.dg/pr107900.f90 : New test

	PR fortran/110224
	* gfortran.dg/pr110224.f90 : New test

	PR fortran/88688
	* gfortran.dg/pr88688.f90 : New test

	PR fortran/94380
	* gfortran.dg/pr94380.f90 : New test

	PR fortran/95398
	* gfortran.dg/pr95398.f90 : Set -std=f2008, bump the line
	numbers in the error tests by two and change the text in two.