[x64] Recognize MOVSXBL.

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 d89daf25306a89882a8c1c8a961f7509ceea3b10..ce7ce56616522b995dc51ce5ce3a1091556ad33c 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -353,6 +353,9 @@ void InstructionSelector::VisitWord32Sar(Node* node) {
     if (mleft.right().Is(16) && m.right().Is(16)) {
       Emit(kX64Movsxwl, g.DefineAsRegister(node), g.Use(mleft.left().node()));
       return;
+    } else if (mleft.right().Is(24) && m.right().Is(24)) {
+      Emit(kX64Movsxbl, g.DefineAsRegister(node), g.Use(mleft.left().node()));
+      return;
     }
   }
   VisitWord32Shift(this, node, kX64Sar32);