clang-format: [JS] Fix line breaks in computed property names.

Before:
  let foo = {
    [someLongKeyHere]: 1,
    someOtherLongKeyHere: 2, [keyLongEnoughToWrap]: 3,
    lastLongKey: 4
  };

After:
  let foo = {
    [someLongKeyHere]: 1,
    someOtherLongKeyHere: 2,
    [keyLongEnoughToWrap]: 3,
    lastLongKey: 4
  };

llvm-svn: 238671
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index d95ff9b..29b8aa1 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -153,8 +153,11 @@
   verifyFormat("var x = {y: (a) => a};");
 
   // Computed keys.
+  verifyFormat("var x = {[a]: 1, b: 2, [c]: 3};");
   verifyFormat("var x = {\n"
                "  [a]: 1,\n"
+               "  b: 2,\n"
+               "  [c]: 3,\n"
                "};");
 }