Add compiler option for counting hotness in compiled code.

For eventually easier profiling of boot classpath and
system server.

bug: 30934496
Test: 674-hotness-compiled

Change-Id: I0f63c644527b74f6ef2649f481c2a1c731bb9f21
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 5c8e46e..51fb4da 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -1276,6 +1276,10 @@
 void CodeGeneratorMIPS::GenerateFrameEntry() {
   __ Bind(&frame_entry_label_);
 
+  if (GetCompilerOptions().CountHotnessInCompiledCode()) {
+    LOG(WARNING) << "Unimplemented hotness update in mips backend";
+  }
+
   bool do_overflow_check =
       FrameNeedsStackCheck(GetFrameSize(), InstructionSet::kMips) || !IsLeafMethod();