clang-format: [JS] support non-null assertions after all identifiers.

Summary:
Previously:
    x = namespace !;

Now:
    x = namespace!;

Reviewers: djasper

Subscribers: klimek

Differential Revision: https://reviews.llvm.org/D33113

llvm-svn: 302893
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 4a2da1a..8387152 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -1799,6 +1799,7 @@
       "            .foo()!\n"
       "            .foo()!;\n",
       getGoogleJSStyleWithColumns(20));
+  verifyFormat("let x = namespace!;\n");
 }
 
 TEST_F(FormatTestJS, Conditional) {