Fix NullPointerException in parser.

Location was not set.

--
MOS_MIGRATED_REVID=96096088
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Parser.java b/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
index 393f540..08dccd9 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
@@ -1416,10 +1416,14 @@
 
   // flow_stmt ::= break_stmt | continue_stmt
   private FlowStatement parseFlowStatement(TokenKind kind) {
+    int start = token.left;
     expect(kind);
-    return (kind == TokenKind.BREAK) ? FlowStatement.BREAK : FlowStatement.CONTINUE;
+    return setLocation(
+        kind == TokenKind.BREAK ? FlowStatement.BREAK : FlowStatement.CONTINUE,
+        start,
+        token.right);
   }
-  
+
   // return_stmt ::= RETURN expr
   private ReturnStatement parseReturnStatement() {
     int start = token.left;