clang-format: [JS] Support quoted object literal keys.

Before:
  var x = {
    a: a,
    b: b, 'c': c,
  };

After:
  var x = {
    a: a,
    b: b,
    'c': c,
  };

llvm-svn: 262291
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 255f11e..39e4ea8 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -205,6 +205,13 @@
   verifyFormat("f({a}, () => {\n"
                "  g();  //\n"
                "});");
+
+  // Keys can be quoted.
+  verifyFormat("var x = {\n"
+               "  a: a,\n"
+               "  b: b,\n"
+               "  'c': c,\n"
+               "};");
 }
 
 TEST_F(FormatTestJS, MethodsInObjectLiterals) {