PR c++/22132

	* call.c (implicit_conversion): Add c_cast_p parameter.
	(standard_conversion): Likewise.  Allow conversions between
	differently-qualified pointer types when performing a C-style
	cast.
	(add_function_candidate): Adjust callee.
	(build_builtin_candidate): Likewise.
	(build_user_type_conversion_1): Likewise.
	(conditional_conversion): Likewise.
	(can_convert_arg): Likewise.
	(can_convert_arg_bad): Likewise.
	(perform_implicit_conversion): Likewise.
	* cp-tree.h (comp_ptr_ttypes_const): Declare.
	* typeck.c (comp_ptr_ttypes_const): Give it external linkage.
	Return bool.

	PR c++/22132
	* g++.dg/expr/cast4.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@102059 138bc75d-0d04-0410-961f-82ee72b054a4