syntax: Fix semicolon printing. Closes #3036

Author: brson

src/libsyntax/parse/token.rs

@@ -136,7 +136,7 @@ fn to_str(in: interner<@~str>, t: token) -> ~str {
       DOT { ~"." }
       ELLIPSIS { ~"..." }
       COMMA { ~"," }
-      SEMI { ~"" }
+      SEMI { ~";" }
       COLON { ~":" }
       MOD_SEP { ~"::" }
       RARROW { ~"->" }

src/test/compile-fail/issue-3036.rs

@@ -0,0 +1,6 @@
+// Testing that semicolon tokens are printed correctly in errors
+
+fn main()
+{
+    let x = 3
+} //~ ERROR: expected `;` but found `}`