AST Matchers test: use arrays instead of vectors

[njames93]

cheers LGTM, probably didn't need a review this one.

[gribozavr2]

probably didn't need a review this one

I don't believe in post-commit review anymore.

clang/unittests/ASTMatchers/ASTMatchersTest.h

public:
   }
 
 private:
   bool *const Verified;
   const std::unique_ptr<BoundNodesCallback> FindResultReviewer;
 };
 
 inline ArrayRef<TestLanguage> langCxx11OrLater() {
-  static std::vector<TestLanguage> Result = {Lang_CXX11, Lang_CXX14, Lang_CXX17,
-                                             Lang_CXX20};
+  static const TestLanguage Result[] = {Lang_CXX11, Lang_CXX14, Lang_CXX17,
   return Result;
 }
 
 inline ArrayRef<TestLanguage> langCxx14OrLater() {
-  static std::vector<TestLanguage> Result = {Lang_CXX14, Lang_CXX17,
-                                             Lang_CXX20};
+  static const TestLanguage Result[] = {Lang_CXX14, Lang_CXX17, Lang_CXX20};
   return Result;
 }
 
 inline ArrayRef<TestLanguage> langCxx17OrLater() {
-  static std::vector<TestLanguage> Result = {Lang_CXX17, Lang_CXX20};
+  static const TestLanguage Result[] = {Lang_CXX17, Lang_CXX20};
   return Result;
 }
 
 inline ArrayRef<TestLanguage> langCxx20OrLater() {
-  static std::vector<TestLanguage> Result = {Lang_CXX20};
+  static const TestLanguage Result[] = {Lang_CXX20};
   return Result;
 }
 
 template <typename T>
 testing::AssertionResult matchesConditionally(
     const Twine &Code, const T &AMatcher, bool ExpectMatch,
     ArrayRef<std::string> CompileArgs,
     const FileContentMappings &VirtualMappedFiles = FileContentMappings(),