Add MachineSignature, which is an encapsulation of the machine types for parameters and return valu…

test/cctest/compiler/test-simplified-lowering.cc

Index: test/cctest/compiler/test-simplified-lowering.cc
diff --git a/test/cctest/compiler/test-simplified-lowering.cc b/test/cctest/compiler/test-simplified-lowering.cc
index 4a654358651df139dce3e78dae51b1ffc6bd74cb..ac72d7892a7c1cc556ef07858f5164006ecf3c28 100644
--- a/test/cctest/compiler/test-simplified-lowering.cc
+++ b/test/cctest/compiler/test-simplified-lowering.cc
@@ -72,9 +72,8 @@ FieldAccess ForJSObjectProperties() {
 
 FieldAccess ForArrayBufferBackingStore() {
   FieldAccess access = {
-      kTaggedBase,                           JSArrayBuffer::kBackingStoreOffset,
-      Handle<Name>(),                        Type::UntaggedPtr(),
-      MachineOperatorBuilder::pointer_rep(),
+      kTaggedBase,         JSArrayBuffer::kBackingStoreOffset, Handle<Name>(),
+      Type::UntaggedPtr(), kMachPtr,
   };
   return access;
 }