Remove CodeItem accessor functions

These are replaced by the accessor helpers.

Bug: 63756964
Test: test-art-host
Test: test/testrunner/testrunner.py --host -j30

Change-Id: Ic93d60b68b684eeb5f69be286b4e15b8f8f97542
diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index dee74e9..729b08e 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -45,6 +45,7 @@
 #include "base/casts.h"
 #include "bytecode_utils.h"
 #include "class_linker.h"
+#include "code_item_accessors-inl.h"
 #include "compiled_method.h"
 #include "dex/verified_method.h"
 #include "driver/compiler_driver.h"
@@ -910,7 +911,8 @@
   }
   ArenaVector<size_t> covered(
       loop_headers.size(), 0, graph.GetAllocator()->Adapter(kArenaAllocMisc));
-  for (const DexInstructionPcPair& pair : code_item.Instructions()) {
+  for (const DexInstructionPcPair& pair : CodeItemInstructionAccessor(&graph.GetDexFile(),
+                                                                      &code_item)) {
     const uint32_t dex_pc = pair.DexPc();
     const Instruction& instruction = pair.Inst();
     if (instruction.IsBranch()) {