Extend JSBuiltinReducer to cover Math.sqrt as well.

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 96501e686b3b7eb0a73ee519c4893d7b14e61af4..5fe7bad81d93ea93fd4cded75390f505d534e40e 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -559,6 +559,12 @@ void InstructionSelector::VisitFloat64Mod(Node* node) {
 }
 
 
+void InstructionSelector::VisitFloat64Sqrt(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kSSEFloat64Sqrt, g.DefineAsRegister(node), g.Use(node->InputAt(0)));
+}
+
+
 void InstructionSelector::VisitInt32AddWithOverflow(Node* node,
                                                     FlagsContinuation* cont) {
   VisitBinop(this, node, kX64Add32, cont);