Remove the old ARM code generator from ART's Optimizing compiler.

The AArch32 VIXL-based code generator has been the default
ARM code generator in ART for some time now. The old ARM
code generator does not compile anymore; retiring it.

Test: test.py
Bug: 63316036
Change-Id: Iab8fbc4ac73eac2c1a809cd7b22fec6b619755db
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index d7e0f51..b9d4700 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -1295,8 +1295,8 @@
         DCHECK(locations->GetLiveRegisters()->ContainsCoreRegister(index_reg.GetCode()));
         if (codegen->IsCoreCalleeSaveRegister(index_reg.GetCode())) {
           // We are about to change the value of `index_reg` (see the
-          // calls to art::arm::Thumb2Assembler::Lsl and
-          // art::arm::Thumb2Assembler::AddConstant below), but it has
+          // calls to art::arm::ArmVIXLMacroAssembler::Lsl and
+          // art::arm::ArmVIXLMacroAssembler::Add below), but it has
           // not been saved by the previous call to
           // art::SlowPathCode::SaveLiveRegisters, as it is a
           // callee-save register --
@@ -8994,7 +8994,7 @@
                                                         Location index) {
   if (kEmitCompilerReadBarrier) {
     // Baker's read barriers shall be handled by the fast path
-    // (CodeGeneratorARM::GenerateReferenceLoadWithBakerReadBarrier).
+    // (CodeGeneratorARMVIXL::GenerateReferenceLoadWithBakerReadBarrier).
     DCHECK(!kUseBakerReadBarrier);
     // If heap poisoning is enabled, unpoisoning will be taken care of
     // by the runtime within the slow path.