Model exceptional edges from call nodes in TurboFan.

src/compiler/opcodes.h

Index: src/compiler/opcodes.h
diff --git a/src/compiler/opcodes.h b/src/compiler/opcodes.h
index a4f8d3ec1696139bff81aab66c4074e9a15e4e5c..31ef304bbacfda421a7358450bb1cb9f74789865 100644
--- a/src/compiler/opcodes.h
+++ b/src/compiler/opcodes.h
@@ -12,6 +12,8 @@
   V(Branch)                      \
   V(IfTrue)                      \
   V(IfFalse)                     \
+  V(IfSuccess)                   \
+  V(IfException)                 \
   V(Switch)                      \
   V(IfValue)                     \
   V(IfDefault)                   \
@@ -299,8 +301,12 @@ class IrOpcode {
     return kInt32Constant <= value && value <= kHeapConstant;
   }
 
-  static bool IsPhiOpcode(Value val) {
-    return val == kPhi || val == kEffectPhi;
+  static bool IsPhiOpcode(Value value) {
+    return value == kPhi || value == kEffectPhi;
+  }
+
+  static bool IsMergeOpcode(Value value) {
+    return value == kMerge || value == kLoop;
   }
 };