Add tests for ARM RT library name

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200539 91177308-0d34-0410-b5e6-96231b3b80d8
clang-format: (JavaScript) Don't crash on empty string literals.

Before, this would lead to a crash:
  f('', true);

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200540 91177308-0d34-0410-b5e6-96231b3b80d8