Revert "Never use classic code generator."

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 4bf84a8585c0b8e8456bd0c16e4e7d4b2bc9fe32..45ffefe8358d8f56a75f40f84917a49fff20f52c 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -2247,6 +2247,15 @@ void FullCodeGenerator::VisitCall(Call* expr) {
       }
     }
   } else {
+    // Call to some other expression.  If the expression is an anonymous
+    // function literal not called in a loop, mark it as one that should
+    // also use the full code generator.
+    FunctionLiteral* lit = fun->AsFunctionLiteral();
+    if (lit != NULL &&
+        lit->name()->Equals(isolate()->heap()->empty_string()) &&
+        loop_depth() == 0) {
+      lit->set_try_full_codegen(true);
+    }
     { PreservePositionScope scope(masm()->positions_recorder());
       VisitForStackValue(fun);
     }