[turbofan] Implement OSR for outer loops.

src/runtime/runtime-compiler.cc

Index: src/runtime/runtime-compiler.cc
diff --git a/src/runtime/runtime-compiler.cc b/src/runtime/runtime-compiler.cc
index 6526dcff8bf3dad096bb6470e541fddcedc4b966..f132d986f5eb4f689c92ae340881df9d804bbbf3 100644
--- a/src/runtime/runtime-compiler.cc
+++ b/src/runtime/runtime-compiler.cc
@@ -301,8 +301,15 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
       // match. Fix heuristics for reenabling optimizations!
       function->shared()->increment_deopt_count();
 
-      // TODO(titzer): Do not install code into the function.
-      function->ReplaceCode(*result);
+      if (result->is_turbofanned()) {
+        // TurboFanned OSR code cannot be installed into the function.
+        // But the function is obviously hot, so optimize it next time.
+        function->ReplaceCode(
+            isolate->builtins()->builtin(Builtins::kCompileOptimized));
+      } else {
+        // Crankshafted OSR code can be installed into the function.
+        function->ReplaceCode(*result);
+      }
       return *result;
     }
   }