Add test for function-like macro invocations with multiple-token arguments.

These are not yet parsed correctly, so these tests fail.

tests/019-define-func-1-arg-multi.c

@@ -0,0 +1,2 @@
+#define foo(x) (x)
+foo(this is more than one word)

tests/020-define-func-2-arg-multi.c

@@ -0,0 +1,2 @@
+#define foo(x,y) x, two fish, red fish, y
+foo(one fish, blue fish)