Add QUES to comp/fe/lexer.rs, rustc can self-lex again.

Author: graydon

src/comp/fe/lexer.rs

@@ -373,6 +373,7 @@ state fn next_token(reader rdr) -> token.token {
     alt (c) {
         // One-byte tokens.
         case (':') { rdr.bump(); ret token.COLON; }
+        case ('?') { rdr.bump(); ret token.QUES; }
         case (';') { rdr.bump(); ret token.SEMI; }
         case (',') { rdr.bump(); ret token.COMMA; }
         case ('.') { rdr.bump(); ret token.DOT; }

src/comp/fe/token.rs

@@ -43,6 +43,7 @@ tag token {
     COMMA;
     SEMI;
     COLON;
+    QUES;
     RARROW;
     SEND;
     LARROW;
@@ -202,6 +203,7 @@ fn to_str(token t) -> str {
         case (COMMA) { ret ","; }
         case (SEMI) { ret ";"; }
         case (COLON) { ret ":"; }
+        case (QUES) { ret "?"; }
         case (RARROW) { ret "->"; }
         case (SEND) { ret "<|"; }
         case (LARROW) { ret "<-"; }