re PR c++/44193 (function types, cv-quals and typename)

re PR c++/44193 (function types, cv-quals and typename)

	PR c++/44193
	* typeck.c (type_memfn_quals): New fn.
	(apply_memfn_quals): New fn.
	(cp_type_quals): Return TYPE_UNQUALIFIED for FUNCTION_TYPE.
	(cp_type_readonly): Use cp_type_quals.
	* cp-tree.h: Add declarations.
	* tree.c (cp_build_qualified_type_real): Don't set, but do
	preserve, quals on FUNCTION_TYPE.
	(strip_typedefs): Use apply_memfn_quals and type_memfn_quals.
	* decl.c (build_ptrmem_type): Likewise.
	(grokdeclarator): Likewise.
	(static_fn_type): Likewise.
	* decl2.c (change_return_type): Likewise.
	(cp_reconstruct_complex_type): Likewise.
	* pt.c (tsubst_function_type): Likewise.
	(unify): Likewise.
	(tsubst): Likewise.  Drop special FUNCTION_TYPE substitution code.

From-SVN: r159596