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

src/compiler/instruction-selector-impl.h

Index: src/compiler/instruction-selector-impl.h
diff --git a/src/compiler/instruction-selector-impl.h b/src/compiler/instruction-selector-impl.h
index cd41e42eff0243ca060416d3857cd63271dd7218..8543aa0b19604dec163c9801a210ec686d0ee691 100644
--- a/src/compiler/instruction-selector-impl.h
+++ b/src/compiler/instruction-selector-impl.h
@@ -72,6 +72,14 @@ class OperandGenerator {
     return Define(node, ToUnallocatedOperand(location, type, GetVReg(node)));
   }
 
+  InstructionOperand DefineAsDualLocation(Node* node,
+                                          LinkageLocation primary_location,
+                                          LinkageLocation secondary_location) {
+    return Define(node,
+                  ToDualLocationUnallocatedOperand(
+                      primary_location, secondary_location, GetVReg(node)));
+  }
+
   InstructionOperand Use(Node* node) {
     return Use(node, UnallocatedOperand(UnallocatedOperand::NONE,
                                         UnallocatedOperand::USED_AT_START,
@@ -211,6 +219,18 @@ class OperandGenerator {
     return operand;
   }
 
+  UnallocatedOperand ToDualLocationUnallocatedOperand(
+      LinkageLocation primary_location, LinkageLocation secondary_location,
+      int virtual_register) {
+    // We only support the primary location being a register and the secondary
+    // one a slot.
+    DCHECK(primary_location.IsRegister() &&
+           secondary_location.IsCalleeFrameSlot());
+    int reg_id = primary_location.AsRegister();
+    int slot_id = secondary_location.AsCalleeFrameSlot();
+    return UnallocatedOperand(reg_id, slot_id, virtual_register);
+  }
+
   UnallocatedOperand ToUnallocatedOperand(LinkageLocation location,
                                           MachineType type,
                                           int virtual_register) {