Allow ExprLit expression macros to be used in patterns.

src/test/run-pass/syntax-extension-source-utils.rs

@@ -43,4 +43,9 @@ pub fn main() {
         [1] == (42 as u8)); // '*'
     // The Windows tests are wrapped in an extra module for some reason
     assert!((m1::m2::where_am_i().as_slice().ends_with("m1::m2")));
+
+    assert!(match (47, "( 2 * 3 ) + 5") {
+        (line!(), stringify!((2*3) + 5)) => true,
+        _ => false
+    })
 }