[turbofan] Add the StackSlot operator to turbofan.

src/compiler/x64/code-generator-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 722 matching lines @@
       Register scratch1 = i.TempRegister(1);
       auto ool = new (zone()) OutOfLineRecordWrite(this, object, operand, value,
                                                    scratch0, scratch1, mode);
       __ movp(operand, value);
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask,
                        not_zero, ool->entry());
       __ bind(ool->exit());
       break;
     }
+    case kArchStackSlot: {
+      FrameOffset offset =
+          frame_access_state()->GetFrameOffset(i.InputInt32(0));
+      Register base;
+      if (offset.from_stack_pointer()) {
+        base = rsp;
+      } else {
+        base = rbp;
+      }
+      __ leaq(i.OutputRegister(), Operand(base, offset.offset()));
+      break;
+    }
     case kX64Add32:
       ASSEMBLE_BINOP(addl);
       break;
     case kX64Add:
       ASSEMBLE_BINOP(addq);
       break;
     case kX64Sub32:
       ASSEMBLE_BINOP(subl);
       break;
     case kX64Sub:
@@ skipping 1382 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8