[Turbofan] Re-enable single splinter.

src/compiler/js-native-context-specialization.cc

Index: src/compiler/js-native-context-specialization.cc
diff --git a/src/compiler/js-native-context-specialization.cc b/src/compiler/js-native-context-specialization.cc
index 3fb7c3d5df85c334f634f04ad718f0f8dd35165f..853ec2db901efffc33d949be6be6f8670692e49e 100644
--- a/src/compiler/js-native-context-specialization.cc
+++ b/src/compiler/js-native-context-specialization.cc
@@ -608,7 +608,7 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadNamed(Node* node) {
 // jump). Generating a single Merge here, which joins all the deoptimizing
 // controls would generate a lot of these basic blocks, however. So this
 // is disabled for now until splintering is fixed.
-#if 0
+#if 1
   // Generate the single "exit" point, where we get if either all map/instance
   // type checks failed, or one of the assumptions inside one of the cases
   // failes (i.e. failing prototype chain check).