[clang-format] Fix buildbot failures

Fix the following buildbot failures by making LangOpts in the unit test
static:
https://lab.llvm.org/buildbot/#/builders/236/builds/11223
https://lab.llvm.org/buildbot/#/builders/239/builds/6968

Author: owenca

clang/unittests/Format/QualifierFixerTest.cpp

@@ -1055,7 +1055,7 @@ TEST_F(QualifierFixerTest, IsQualifierType) {
   ConfiguredTokens.push_back(tok::kw_constexpr);
   ConfiguredTokens.push_back(tok::kw_friend);
 
-  LangOptions LangOpts{getFormattingLangOpts()};
+  static const LangOptions LangOpts{getFormattingLangOpts()};
 
   auto Tokens = annotate(
       "const static inline auto restrict int double long constexpr friend");