[qfcc] Use a union to manage function attributes

Same idea as the specifiers, but makes checking function types are the
same much easier.

tools/qfcc/include/type.h

@@ -39,7 +39,12 @@ typedef struct ty_func_s {
 	struct type_s *type;
 	int         num_params;
 	struct type_s **param_types;
-	int         no_va_list;		///< don't inject va_list for ... function
+	union {
+		struct {
+			unsigned    no_va_list:1;///< don't inject va_list for ... function
+		};
+		unsigned    attribute_bits;
+	};
 } ty_func_t;
 
 typedef struct ty_fldptr_s {

tools/qfcc/source/class.c

@@ -90,7 +90,7 @@ type_t      type_IMP = {
 	.alignment = 1,
 	.width = 1,
 	.meta = ty_basic,
-	{{&type_id, -3, IMP_params, 1}},
+	{{&type_id, -3, IMP_params, .no_va_list = 1}},
 };
 type_t      type_super = {
 	.type = ev_invalid,

tools/qfcc/source/type.c

@@ -379,7 +379,7 @@ types_same (type_t *a, type_t *b)
 				case ev_func:
 					if (a->t.func.type != b->t.func.type
 						|| a->t.func.num_params != b->t.func.num_params
-						|| a->t.func.no_va_list != b->t.func.no_va_list)
+						|| a->t.func.attribute_bits != b->t.func.attribute_bits)
 						return 0;
 					count = a->t.func.num_params;
 					if (count < 0)