clang-format: [JS] Support alternative operator names as identifiers.

Before:
  not. and . or . not_eq = 1;

After:
  not.and.or.not_eq = 1;

llvm-svn: 217179
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 5bb1a38..fcddba7 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -83,6 +83,10 @@
   verifyFormat("var b = a.map((x) => x + 1);");
 }
 
+TEST_F(FormatTestJS, LiteralOperatorsCanBeKeywords) {
+  verifyFormat("not.and.or.not_eq = 1;");
+}
+
 TEST_F(FormatTestJS, ES6DestructuringAssignment) {
   verifyFormat("var [a, b, c] = [1, 2, 3];");
   verifyFormat("var {a, b} = {a: 1, b: 2};");