[turbofan] Spill rsi and rdi in their existing locations.

src/compiler/linkage.cc

Index: src/compiler/linkage.cc
diff --git a/src/compiler/linkage.cc b/src/compiler/linkage.cc
index c3f6074fa635453b5945947e60246793f981fb26..ced550de2d9bcf8dccd7c21d06f43fdc8af47a85 100644
--- a/src/compiler/linkage.cc
+++ b/src/compiler/linkage.cc
@@ -565,6 +565,28 @@ LinkageLocation Linkage::GetOsrValueLocation(int index) const {
     return incoming_->GetInputLocation(parameter_index);
   }
 }
+
+
+bool Linkage::ParameterHasSecondaryLocation(int index) const {
+  if (incoming_->kind() != CallDescriptor::kCallJSFunction) return false;
+  LinkageLocation loc = GetParameterLocation(index);
+  return (loc == regloc(kJSFunctionRegister) ||
+          loc == regloc(kContextRegister));
+}
+
+LinkageLocation Linkage::GetParameterSecondaryLocation(int index) const {
+  DCHECK(ParameterHasSecondaryLocation(index));
+  LinkageLocation loc = GetParameterLocation(index);
+
+  if (loc == regloc(kJSFunctionRegister)) {
+    return LinkageLocation::ForCalleeFrameSlot(Frame::kJSFunctionSlot);
+  } else {
+    DCHECK(loc == regloc(kContextRegister));
+    return LinkageLocation::ForCalleeFrameSlot(Frame::kContextSlot);
+  }
+}
+
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8