[turbofan] Do not produce 2 ops for Int32AddWithOverflow.

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index 41208bedb4d203e35a0e790212703984c973cc09..0b869544ca9f33fb24b05058e72dcaff511b79e4 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -1786,9 +1786,10 @@ void InstructionSelector::VisitInt32AddWithOverflow(Node* node) {
   if (Node* ovf = NodeProperties::FindProjection(node, 1)) {
     FlagsContinuation cont = FlagsContinuation::ForSet(kOverflow, ovf);
     VisitBinop(this, node, kX64Add32, &cont);
+  } else {

[Benedikt Meurer, 2016/03/03 17:48:09]

Please leave the version w/o the else, and instead add return above similar to
the rest of the file.

+    FlagsContinuation cont;
+    VisitBinop(this, node, kX64Add32, &cont);
   }
-  FlagsContinuation cont;
-  VisitBinop(this, node, kX64Add32, &cont);
 }