Introduce runtime function %OptimizeFunctionOnNextCall to manually trigger optimization.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 37c51d703db1679ba037990d411533734bfa9de5..0dac18e980b61cf90aaf70e2e63517665ba87b7d 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -3323,6 +3323,11 @@ bool JSFunction::IsOptimized() {
 }
 
 
+bool JSFunction::IsOptimizable() {
+  return code()->kind() == Code::FUNCTION && code()->optimizable();
+}
+
+
 bool JSFunction::IsMarkedForLazyRecompilation() {
   return code() == GetIsolate()->builtins()->builtin(Builtins::kLazyRecompile);
 }