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

src/compiler/register-allocator-verifier.h

Index: src/compiler/register-allocator-verifier.h
diff --git a/src/compiler/register-allocator-verifier.h b/src/compiler/register-allocator-verifier.h
index 87b5cfbb7a06e23d03b42a815fe45e0a89a41ad4..f3ab54f01818788ae70fb2a6aa59714aefd9e776 100644
--- a/src/compiler/register-allocator-verifier.h
+++ b/src/compiler/register-allocator-verifier.h
@@ -36,12 +36,14 @@ class RegisterAllocatorVerifier final : public ZoneObject {
     kNone,
     kNoneDouble,
     kExplicit,
-    kSameAsFirst
+    kSameAsFirst,
+    kRegisterAndSlot
   };
 
   struct OperandConstraint {
     ConstraintType type_;
     int value_;  // subkind index when relevant
+    int spilled_slot_;
     int virtual_register_;
   };