ART: Clean up unused using declarations

Make tidy happy, and enable checking.

Test: mmma art
Change-Id: I9e18e80b3f37dd2aeb8ecd1c25abe4d5cf2f1c45
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index e2ca515..760b1dd 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -64,7 +64,6 @@
 using helpers::FPRegisterFrom;
 using helpers::HeapOperand;
 using helpers::HeapOperandFrom;
-using helpers::InputCPURegisterAt;
 using helpers::InputCPURegisterOrZeroRegAt;
 using helpers::InputFPRegisterAt;
 using helpers::InputOperandAt;
@@ -78,7 +77,6 @@
 using helpers::OutputRegister;
 using helpers::QRegisterFrom;
 using helpers::RegisterFrom;
-using helpers::SRegisterFrom;
 using helpers::StackOperandFrom;
 using helpers::VIXLRegCodeFromART;
 using helpers::WRegisterFrom;
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 5ae64dd..6d6d1a2 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -48,7 +48,6 @@
 
 using helpers::DRegisterFrom;
 using helpers::DWARFReg;
-using helpers::HighDRegisterFrom;
 using helpers::HighRegisterFrom;
 using helpers::InputDRegisterAt;
 using helpers::InputOperandAt;
diff --git a/compiler/optimizing/intrinsics_arm_vixl.cc b/compiler/optimizing/intrinsics_arm_vixl.cc
index f11e5a1..2963308 100644
--- a/compiler/optimizing/intrinsics_arm_vixl.cc
+++ b/compiler/optimizing/intrinsics_arm_vixl.cc
@@ -41,19 +41,15 @@
 using helpers::InputDRegisterAt;
 using helpers::InputRegisterAt;
 using helpers::InputSRegisterAt;
-using helpers::InputVRegisterAt;
 using helpers::Int32ConstantFrom;
 using helpers::LocationFrom;
 using helpers::LowRegisterFrom;
 using helpers::LowSRegisterFrom;
 using helpers::HighSRegisterFrom;
 using helpers::OutputDRegister;
-using helpers::OutputSRegister;
 using helpers::OutputRegister;
-using helpers::OutputVRegister;
 using helpers::RegisterFrom;
 using helpers::SRegisterFrom;
-using helpers::DRegisterFromS;
 
 using namespace vixl::aarch32;  // NOLINT(build/namespaces)
 
diff --git a/compiler/optimizing/optimizing_cfi_test.cc b/compiler/optimizing/optimizing_cfi_test.cc
index 1c1cf28..04301f5 100644
--- a/compiler/optimizing/optimizing_cfi_test.cc
+++ b/compiler/optimizing/optimizing_cfi_test.cc
@@ -34,8 +34,6 @@
 
 namespace vixl32 = vixl::aarch32;
 
-using vixl32::r0;
-
 namespace art {
 
 // Run the tests only on host.
@@ -194,6 +192,7 @@
 
 #ifdef ART_ENABLE_CODEGEN_arm
 TEST_F(OptimizingCFITest, kThumb2Adjust) {
+  using vixl32::r0;
   std::vector<uint8_t> expected_asm(
       expected_asm_kThumb2_adjust,
       expected_asm_kThumb2_adjust + arraysize(expected_asm_kThumb2_adjust));
diff --git a/compiler/utils/arm/assembler_arm_vixl.cc b/compiler/utils/arm/assembler_arm_vixl.cc
index 05250a4..ebb631e 100644
--- a/compiler/utils/arm/assembler_arm_vixl.cc
+++ b/compiler/utils/arm/assembler_arm_vixl.cc
@@ -26,9 +26,6 @@
 
 using namespace vixl::aarch32;  // NOLINT(build/namespaces)
 
-using vixl::ExactAssemblyScope;
-using vixl::CodeBufferCheckScope;
-
 namespace art {
 namespace arm {