Introduce intrinsics for double values in Javascript.

src/full-codegen.cc

Index: src/full-codegen.cc
diff --git a/src/full-codegen.cc b/src/full-codegen.cc
index 16bb6c0d01330e73bacb096ed5d70619ed615078..b98483208ca7120db7b1879ca3739af741371875 100644
--- a/src/full-codegen.cc
+++ b/src/full-codegen.cc
@@ -950,6 +950,34 @@ void FullCodeGenerator::EmitDebugBreakInOptimizedCode(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitDoubleHi(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  ASSERT(args->length() == 1);
+  VisitForStackValue(args->at(0));
+  masm()->CallRuntime(Runtime::kDoubleHi, 1);
+  context()->Plug(result_register());
+}
+
+
+void FullCodeGenerator::EmitDoubleLo(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  ASSERT(args->length() == 1);
+  VisitForStackValue(args->at(0));
+  masm()->CallRuntime(Runtime::kDoubleLo, 1);
+  context()->Plug(result_register());
+}
+
+
+void FullCodeGenerator::EmitConstructDouble(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  ASSERT(args->length() == 2);
+  VisitForStackValue(args->at(0));
+  VisitForStackValue(args->at(1));
+  masm()->CallRuntime(Runtime::kConstructDouble, 2);
+  context()->Plug(result_register());
+}
+
+
 void FullCodeGenerator::VisitBinaryOperation(BinaryOperation* expr) {
   switch (expr->op()) {
     case Token::COMMA: