Skylark: Forbid break/continue in BUILD files.

--
MOS_MIGRATED_REVID=96095253
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java b/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java
index 5f33718..fd8478d 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java
@@ -351,6 +351,13 @@
   }
 
   @Test
+  public void testBreak() {
+    setFailFast(false);
+    parseExpression("break");
+    assertContainsEvent("syntax error at 'break': expected expression");
+  }
+
+  @Test
   public void testTry() {
     setFailFast(false);
     parseExpression("try: 1 + 1");