clang-format: [JS] Fix failing format with TypeScript casts.

Before, this could be formatted at all (with BracketAlignmentStyle
AlwaysBreak):

  foo = <Bar[]>[
    1, /* */
    2
  ];

llvm-svn: 272668
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 8410a0c..f71571c 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -1205,6 +1205,10 @@
 TEST_F(FormatTestJS, CastSyntax) {
   verifyFormat("var x = <type>foo;");
   verifyFormat("var x = foo as type;");
+  verifyFormat("foo = <Bar[]>[\n"
+               "  1,  //\n"
+               "  2\n"
+               "];");
 }
 
 TEST_F(FormatTestJS, TypeArguments) {