[NFC][clangd] cleaning up unused "using"

[kuhnel]

Summary

Cleaning up unused "using" declarations.
This patch was generated from automatically applyning clang-tidy fixes.

[kadircet]

thanks!

clang-tools-extra/clangd/index/YAMLSerialization.cpp

 using clang::clangd::RelationKind;
 using clang::clangd::Symbol;
 using clang::clangd::SymbolID;
 using clang::clangd::SymbolLocation;
 using clang::clangd::SymbolOrigin;
 using clang::index::SymbolInfo;
 using clang::index::SymbolKind;
 using clang::index::SymbolLanguage;
-using clang::index::SymbolRole;
 using clang::tooling::CompileCommand;
 
 // Helper to (de)serialize the SymbolID. We serialize it as a hex string.
 struct NormalizedSymbolID {
   NormalizedSymbolID(IO &) {}
   NormalizedSymbolID(IO &, const SymbolID &ID) {
     llvm::raw_string_ostream OS(HexString);
     OS << ID;

clang-tools-extra/clangd/unittests/ClangdTests.cpp

 #include <vector>
 
 namespace clang {
 namespace clangd {
 
 namespace {
 
 using ::testing::AllOf;
-using ::testing::Contains;
 using ::testing::ElementsAre;
 using ::testing::Field;
-using ::testing::Gt;
 using ::testing::IsEmpty;
 using ::testing::Pair;
 using ::testing::SizeIs;
 using ::testing::UnorderedElementsAre;
 
 MATCHER_P2(DeclAt, File, Range, "") {
   return arg.PreferredDeclaration ==
          Location{URIForFile::canonicalize(File, testRoot()), Range};

clang-tools-extra/clangd/unittests/GlobalCompilationDatabaseTests.cpp

 namespace {
 using ::testing::AllOf;
 using ::testing::Contains;
 using ::testing::ElementsAre;
 using ::testing::EndsWith;
 using ::testing::HasSubstr;
 using ::testing::IsEmpty;
 using ::testing::Not;
-using ::testing::StartsWith;
 using ::testing::UnorderedElementsAre;
 
 TEST(GlobalCompilationDatabaseTest, FallbackCommand) {
   MockFS TFS;
   DirectoryBasedGlobalCompilationDatabase DB(TFS);
   auto Cmd = DB.getFallbackCommand(testPath("foo/bar.cc"));
   EXPECT_EQ(Cmd.Directory, testPath("foo"));
   EXPECT_THAT(Cmd.CommandLine, ElementsAre("clang", testPath("foo/bar.cc")));

clang-tools-extra/clangd/unittests/HeadersTests.cpp

 namespace {
 
 using ::testing::AllOf;
 using ::testing::Contains;
 using ::testing::ElementsAre;
 using ::testing::IsEmpty;
 using ::testing::Not;
 using ::testing::UnorderedElementsAre;
-using ::testing::UnorderedElementsAreArray;
 
 class HeadersTest : public ::testing::Test {
 public:
   HeadersTest() {
     CDB.ExtraClangFlags = {SearchDirArg.c_str()};
     FS.Files[MainFile] = "";
     // Make sure directory sub/ exists.
     FS.Files[testPath("sub/EMPTY")] = "";

clang-tools-extra/clangd/unittests/IndexTests.cpp

 #include "index/Symbol.h"
 #include "clang/Index/IndexSymbol.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include <utility>
 
 using ::testing::_;
 using ::testing::AllOf;
-using ::testing::AnyOf;
 using ::testing::ElementsAre;
 using ::testing::IsEmpty;
 using ::testing::Pair;
 using ::testing::Pointee;
 using ::testing::UnorderedElementsAre;
 
 namespace clang {
 namespace clangd {

clang-tools-extra/clangd/unittests/RIFFTests.cpp

 //===-- RIFFTests.cpp - Binary container unit tests -----------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "RIFF.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
 namespace clang {
 namespace clangd {
 namespace {
-using ::testing::ElementsAre;
 
 TEST(RIFFTest, File) {
   riff::File File{riff::fourCC("test"),
                   {
                       {riff::fourCC("even"), "abcd"},
                       {riff::fourCC("oddd"), "abcde"},
                   }};
   llvm::StringRef Serialized = llvm::StringRef("RIFF\x1e\0\0\0test"