[turbofan] Handle void returns in instruction selector.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 4981f6427aaa412efb9146020d900abdee088699..01c5f6f3c64e963f4f95cee8fcfabd749710ebfb 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1000,9 +1000,13 @@ void InstructionSelector::VisitGoto(BasicBlock* target) {
 void InstructionSelector::VisitReturn(Node* value) {
   DCHECK_NOT_NULL(value);
   OperandGenerator g(this);
-  Emit(kArchRet, g.NoOutput(),
-       g.UseLocation(value, linkage()->GetReturnLocation(),
-                     linkage()->GetReturnType()));
+  if (linkage()->GetIncomingDescriptor()->ReturnCount() == 0) {
+    Emit(kArchRet, g.NoOutput(), g.Use(value));

[Jarin, 2015/08/04 12:38:30]

Any reason for calling g.Use(value)? This might keep that value alive for longer
than it needs to be.

+  } else {
+    Emit(kArchRet, g.NoOutput(),
+         g.UseLocation(value, linkage()->GetReturnLocation(),
+                       linkage()->GetReturnType()));
+  }
 }