Use the local name instead of the original name in the check for name conflicts
between a hosting program unit and use-associated symbols
in that program unit.

fortran/
	PR fortran/63744
	* module.c (check_for_ambiguous): Change argument type
	from gfc_symbol to gfc_symtree.  Check local (symtree) name
	instead of original (symbol) name.
	(read_module): Update caller.

testsuite/
	PR fortran/63744
	gfortran.dg/use_rename_8.f90: New.

From-SVN: r220515