Allow format_args to accept a raw string literal

gcc/rust/ChangeLog:

	* expand/rust-macro-builtins-format-args.cc
	(format_args_parse_arguments): Accept a RAW_STRING_LITERAL token
	as the first argument.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>

Author: powerboat9

gcc/rust/expand/rust-macro-builtins-format-args.cc

@@ -52,8 +52,15 @@ format_args_parse_arguments (AST::MacroInvocData &invoc)
 
   // TODO: Handle the case where we're not parsing a string literal (macro
   // invocation for e.g.)
-  if (parser.peek_current_token ()->get_id () == STRING_LITERAL)
-    format_expr = parser.parse_literal_expr ();
+  switch (parser.peek_current_token ()->get_id ())
+    {
+    case STRING_LITERAL:
+    case RAW_STRING_LITERAL:
+      format_expr = parser.parse_literal_expr ();
+    default:
+      // do nothing
+      ;
+    }
 
   rust_assert (format_expr);