Remove ArtCode.

- Instead use OatQuickMethodHeader.
- Various cleanups now that we don't have all those
  ArtMethod -> ArtCode -> OatQuickMethodHeader indirections.

As a consequence of this cleanup, exception handling got a bit
faster.

ParserCombinators benchmark (exception intensive) on x64: (lower is better)
Before:
ParserCombinators(RunTime): 1062500.0 us.
After:
ParserCombinators(RunTime): 833000.0 us.

Change-Id: Idac917b6f1b0dc254ad68fb3781cd61bccadb0f3
diff --git a/runtime/entrypoints/quick/quick_trampoline_entrypoints_test.cc b/runtime/entrypoints/quick/quick_trampoline_entrypoints_test.cc
index 5299394..4e85913 100644
--- a/runtime/entrypoints/quick/quick_trampoline_entrypoints_test.cc
+++ b/runtime/entrypoints/quick/quick_trampoline_entrypoints_test.cc
@@ -49,7 +49,7 @@
   static void CheckFrameSize(InstructionSet isa, Runtime::CalleeSaveType type, uint32_t save_size)
       NO_THREAD_SAFETY_ANALYSIS {
     ArtMethod* save_method = CreateCalleeSaveMethod(isa, type);
-    QuickMethodFrameInfo frame_info = ArtCode(save_method).GetQuickFrameInfo();
+    QuickMethodFrameInfo frame_info = Runtime::Current()->GetRuntimeMethodFrameInfo(save_method);
     EXPECT_EQ(frame_info.FrameSizeInBytes(), save_size) << "Expected and real size differs for "
         << type << " core spills=" << std::hex << frame_info.CoreSpillMask() << " fp spills="
         << frame_info.FpSpillMask() << std::dec << " ISA " << isa;
@@ -58,8 +58,8 @@
   static void CheckPCOffset(InstructionSet isa, Runtime::CalleeSaveType type, size_t pc_offset)
       NO_THREAD_SAFETY_ANALYSIS {
     ArtMethod* save_method = CreateCalleeSaveMethod(isa, type);
-    QuickMethodFrameInfo frame_info = ArtCode(save_method).GetQuickFrameInfo();
-    EXPECT_EQ(ArtCode(save_method).GetReturnPcOffset().SizeValue(), pc_offset)
+    QuickMethodFrameInfo frame_info = Runtime::Current()->GetRuntimeMethodFrameInfo(save_method);
+    EXPECT_EQ(frame_info.GetReturnPcOffset(), pc_offset)
         << "Expected and real pc offset differs for " << type
         << " core spills=" << std::hex << frame_info.CoreSpillMask()
         << " fp spills=" << frame_info.FpSpillMask() << std::dec << " ISA " << isa;