Always use selector type for method type encodings.

In the new ABI, we use the legacy type encoding in the selector and the
extended type encoding in the types field.  We want to only expose the
legacy type encoding through existing APIs.

encoding2.c

@@ -386,7 +386,7 @@ void method_getReturnType(Method method, char *dst, size_t dst_len)
 {
 	if (NULL == method) { return; }
 	//TODO: Coped and pasted code.  Factor it out.
-	const char *types = method->types;
+	const char *types = method_getTypeEncoding(method);
 	size_t length = lengthOfTypeEncoding(types);
 	if (length < dst_len)
 	{
@@ -402,7 +402,7 @@ void method_getReturnType(Method method, char *dst, size_t dst_len)
 const char *method_getTypeEncoding(Method method)
 {
 	if (NULL == method) { return NULL; }
-	return method->types;
+	return sel_getType_np(method->selector);
 }
 
 
@@ -412,7 +412,7 @@ void method_getArgumentType(Method method,
                             size_t dst_len)
 {
 	if (NULL == method) { return; }
-	const char *types = findParameterStart(method->types, index);
+	const char *types = findParameterStart(method_getTypeEncoding(method), index);
 	if (NULL == types)
 	{
 		strncpy(dst, "", dst_len);
@@ -433,7 +433,7 @@ void method_getArgumentType(Method method,
 unsigned method_getNumberOfArguments(Method method)
 {
 	if (NULL == method) { return 0; }
-	const char *types = method->types;
+	const char *types = method_getTypeEncoding(method);
 	unsigned int count = 0;
 	while('\0' != *types)
 	{
@@ -452,7 +452,7 @@ unsigned method_get_number_of_arguments(struct objc_method *method)
 char* method_copyArgumentType(Method method, unsigned int index)
 {
 	if (NULL == method) { return NULL; }
-	const char *types = findParameterStart(method->types, index);
+	const char *types = findParameterStart(method_getTypeEncoding(method), index);
 	if (NULL == types)
 	{
 		return NULL;
@@ -463,7 +463,7 @@ char* method_copyArgumentType(Method method, unsigned int index)
 char* method_copyReturnType(Method method)
 {
 	if (NULL == method) { return NULL; }
-	return copyTypeEncoding(method->types);
+	return copyTypeEncoding(method_getTypeEncoding(method));
 }
 
 unsigned objc_get_type_qualifiers (const char *type)