[turbofan]: Elide extra move when accessing stack or frame register

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 b34a914efcca285a4a80aa6470be2b16a7d8893b..0dde2a4e6c4e405d0edad075ce390eb2f0cc83e6 100644
--- a/src/compiler/instruction-selector-impl.h
+++ b/src/compiler/instruction-selector-impl.h
@@ -75,15 +75,29 @@ class OperandGenerator {
   }
 
   InstructionOperand Use(Node* node) {
-    return Use(node, UnallocatedOperand(UnallocatedOperand::NONE,
-                                        UnallocatedOperand::USED_AT_START,
-                                        GetVReg(node)));
+    IrOpcode::Value opcode = node->opcode();
+    if (opcode == IrOpcode::kLoadFramePointer) {
+      return FramePointerOperand();
+    } else if (opcode == IrOpcode::kLoadStackPointer) {
+      return StackPointerOperand();
+    } else {
+      return Use(node, UnallocatedOperand(UnallocatedOperand::NONE,
+                                          UnallocatedOperand::USED_AT_START,
+                                          GetVReg(node)));
+    }
   }
 
   InstructionOperand UseRegister(Node* node) {
-    return Use(node, UnallocatedOperand(UnallocatedOperand::MUST_HAVE_REGISTER,
-                                        UnallocatedOperand::USED_AT_START,
-                                        GetVReg(node)));
+    IrOpcode::Value opcode = node->opcode();
+    if (opcode == IrOpcode::kLoadFramePointer) {
+      return FramePointerOperand();
+    } else if (opcode == IrOpcode::kLoadStackPointer) {
+      return StackPointerOperand();
+    } else {
+      return Use(node, UnallocatedOperand(
+                           UnallocatedOperand::MUST_HAVE_REGISTER,
+                           UnallocatedOperand::USED_AT_START, GetVReg(node)));
+    }
   }
 
   InstructionOperand UseUniqueSlot(Node* node) {