clang-format: [JS] Support ES6 destructuring assignments.

Before:
  var[a, b, c] = [1, 2, 3];

After:
  var [a, b, c] = [1, 2, 3];

llvm-svn: 209113
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index c10dc96..f38bf89 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -81,6 +81,11 @@
   verifyFormat("var b = a.map((x) => x + 1);");
 }
 
+TEST_F(FormatTestJS, ES6DestructuringAssignment) {
+  verifyFormat("var [a, b, c] = [1, 2, 3];");
+  verifyFormat("var {a, b} = {a: 1, b: 2};");
+}
+
 TEST_F(FormatTestJS, SpacesInContainerLiterals) {
   verifyFormat("var arr = [1, 2, 3];");
   verifyFormat("var obj = {a: 1, b: 2, c: 3};");