[clang] Remove unused using decls (NFC)

Identified with misc-unused-using-decls.

Author: kazutakahirata

clang/unittests/AST/ASTImporterTest.cpp

@@ -24,7 +24,6 @@ namespace clang {
 namespace ast_matchers {
 
 using internal::Matcher;
-using internal::BindableMatcher;
 
 static const RecordDecl *getRecordDeclOfFriend(FriendDecl *FD) {
   QualType Ty = FD->getFriendType()->getType().getCanonicalType();

clang/unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp

@@ -47,7 +47,6 @@ using namespace test;
 using namespace ast_matchers;
 using llvm::IsStringMapEntry;
 using ::testing::DescribeMatcher;
-using ::testing::ElementsAre;
 using ::testing::IsEmpty;
 using ::testing::NotNull;
 using ::testing::Test;

clang/unittests/Format/FormatTestRawStrings.cpp

@@ -17,9 +17,6 @@
 
 #define DEBUG_TYPE "format-test"
 
-using clang::tooling::ReplacementTest;
-using clang::tooling::toReplacements;
-
 namespace clang {
 namespace format {
 namespace {

clang/unittests/Tooling/RangeSelectorTest.cpp

@@ -28,7 +28,6 @@ using ::llvm::HasValue;
 using ::llvm::StringError;
 using ::testing::AllOf;
 using ::testing::HasSubstr;
-using ::testing::Property;
 
 using MatchResult = MatchFinder::MatchResult;