[llvm] Remove unused using decls (NFC)

Identified with misc-unused-using-decls.

Author: kazutakahirata

llvm/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp

@@ -37,7 +37,6 @@
 using namespace llvm;
 using namespace dwarf;
 using namespace utils;
-using ::testing::HasSubstr;
 
 namespace {
 

llvm/unittests/DebugInfo/DWARF/DWARFDieTest.cpp

@@ -15,7 +15,6 @@
 
 using namespace llvm;
 using namespace llvm::dwarf;
-using object::SectionedAddress;
 
 namespace {
 

llvm/unittests/DebugInfo/DWARF/DWARFLocationExpressionTest.cpp

@@ -11,7 +11,6 @@
 #include "gtest/gtest.h"
 
 using namespace llvm;
-using object::SectionedAddress;
 
 TEST(DWARFLocationExpression, Equality) {
   EXPECT_EQ((DWARFLocationExpression{std::nullopt, {}}),

llvm/unittests/FuzzMutate/OperationsTest.cpp

@@ -48,7 +48,6 @@ using testing::Each;
 using testing::ElementsAre;
 using testing::Eq;
 using testing::Ge;
-using testing::NotNull;
 using testing::PrintToString;
 using testing::SizeIs;
 using testing::Truly;

llvm/unittests/Support/YAMLIOTest.cpp

@@ -23,7 +23,6 @@ using llvm::yaml::Hex32;
 using llvm::yaml::Hex64;
 using llvm::yaml::Hex8;
 using llvm::yaml::Input;
-using llvm::yaml::IO;
 using llvm::yaml::isNumeric;
 using llvm::yaml::MappingNormalization;
 using llvm::yaml::MappingTraits;

llvm/unittests/Transforms/Scalar/LoopPassManagerTest.cpp

@@ -33,7 +33,6 @@ namespace {
 
 using testing::DoDefault;
 using testing::Return;
-using testing::Expectation;
 using testing::Invoke;
 using testing::InvokeWithoutArgs;
 using testing::_;

llvm/unittests/XRay/FDRBlockVerifierTest.cpp

@@ -17,8 +17,6 @@ namespace llvm {
 namespace xray {
 namespace {
 
-using ::testing::ElementsAre;
-using ::testing::Not;
 using ::testing::SizeIs;
 
 TEST(FDRBlockVerifierTest, ValidBlocksV3) {

llvm/unittests/tools/llvm-cfi-verify/GraphBuilder.cpp

@@ -49,10 +49,8 @@ using ::testing::IsEmpty;
 using ::testing::Matches;
 using ::testing::Pair;
 using ::testing::PrintToString;
-using ::testing::Property;
 using ::testing::SizeIs;
 using ::testing::UnorderedElementsAre;
-using ::testing::Value;
 
 namespace llvm {
 namespace cfi_verify {

mlir/unittests/Bytecode/BytecodeTest.cpp

@@ -21,8 +21,6 @@
 using namespace llvm;
 using namespace mlir;
 
-using ::testing::StartsWith;
-
 StringLiteral IRWithResources = R"(
 module @TestDialectResources attributes {
   bytecode.test = dense_resource<resource> : tensor<4xi32>