Add a new AST node for augmented assignments in Skylark

--
PiperOrigin-RevId: 142438943
MOS_MIGRATED_REVID=142438943
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 3387fac..8cd35f2 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
@@ -428,11 +428,11 @@
 
   @Test
   public void testAugmentedAssign() throws Exception {
-    assertEquals("[x = x + 1\n]", parseFile("x += 1").toString());
-    assertEquals("[x = x - 1\n]", parseFile("x -= 1").toString());
-    assertEquals("[x = x * 1\n]", parseFile("x *= 1").toString());
-    assertEquals("[x = x / 1\n]", parseFile("x /= 1").toString());
-    assertEquals("[x = x % 1\n]", parseFile("x %= 1").toString());
+    assertEquals("[x += 1\n]", parseFile("x += 1").toString());
+    assertEquals("[x -= 1\n]", parseFile("x -= 1").toString());
+    assertEquals("[x *= 1\n]", parseFile("x *= 1").toString());
+    assertEquals("[x /= 1\n]", parseFile("x /= 1").toString());
+    assertEquals("[x %= 1\n]", parseFile("x %= 1").toString());
   }
 
   @Test