JIT baseline: trigger optimized compilation on hotness threshold.

- Add a new hotness count in the ProfilingInfo to not conflict with
interpreter hotness which may use it for OSR.
- Add a baseline flag in the OatQuickMethodHeader to identify baseline
compiled methods.
- Add a -Xusetieredjit flag to experiment and test.

Bug: 119800099
Test: test.py with Xusetieredjit to true

Change-Id: I8512853f869f1312e3edc60bf64413dee9143c52
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 5537a4a..2e8d9b3 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -603,6 +603,8 @@
   void MaybeGenerateInlineCacheCheck(HInstruction* instruction, CpuRegister cls);
 
 
+  void MaybeIncrementHotness(bool is_frame_entry);
+
   // When we don't know the proper offset for the value, we use kDummy32BitOffset.
   // We will fix this up in the linker later to have the right value.
   static constexpr int32_t kDummy32BitOffset = 256;