Investigate & fix issues around usage_count and deoptimization_count

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 44591af3af265783e765cc5d8ae2b3bf85b63443..d3b8f3cac6547e5ffe86343f98fac22ae89a6c51 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -70,6 +70,7 @@ DEFINE_FLAG(int, max_speculative_inlining_attempts, 1,
     "Max number of attempts with speculative inlining (precompilation only)");
 
 DECLARE_FLAG(bool, background_compilation);
+DECLARE_FLAG(bool, huge_method_cutoff_in_code_size);
 DECLARE_FLAG(bool, load_deferred_eagerly);
 DECLARE_FLAG(bool, trace_failed_optimization_attempts);
 DECLARE_FLAG(bool, trace_inlining_intervals);
@@ -466,6 +467,11 @@ void CompileParsedFunctionHelper::FinalizeCompilation(
       Code::FinalizeCode(function, assembler, optimized()));
   code.set_is_optimized(optimized());
   code.set_owner(function);
+  if (!function.IsOptimizable()) {
+    // A function with huge unoptimized code canb become non-optimizable

[Florian Schneider, 2016/01/04 11:31:37]

s/canb/can/

[srdjan, 2016/01/04 18:29:53]

Done.

+    // after generating unoptimized code.
+    function.set_usage_counter(INT_MIN);
+  }
 
   const Array& intervals = graph_compiler->inlined_code_intervals();
   INC_STAT(thread(), total_code_size,