[stubs] Remove dead RepresentationFromType helper.

R=mvstanton@chromium.org

Review-Url: https://codereview.chromium.org/2312723002
Cr-Commit-Position: refs/heads/master@{#39173}

src/code-stubs.cc

@@ -5836,23 +5836,6 @@ ArrayConstructorStub::ArrayConstructorStub(Isolate* isolate,
 InternalArrayConstructorStub::InternalArrayConstructorStub(Isolate* isolate)
     : PlatformCodeStub(isolate) {}
 
-Representation RepresentationFromType(AstType* type) {
-  if (type->Is(AstType::UntaggedIntegral())) {
-    return Representation::Integer32();
-  }
-
-  if (type->Is(AstType::TaggedSigned())) {
-    return Representation::Smi();
-  }
-
-  if (type->Is(AstType::UntaggedPointer())) {
-    return Representation::External();
-  }
-
-  DCHECK(!type->Is(AstType::Untagged()));
-  return Representation::Tagged();
-}
-
 Representation RepresentationFromMachineType(MachineType type) {
   if (type == MachineType::Int32()) {
     return Representation::Integer32();

src/code-stubs.h

@@ -3224,7 +3224,6 @@ class ToObjectStub final : public TurboFanCodeStub {
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 
-extern Representation RepresentationFromType(Type* type);
 extern Representation RepresentationFromMachineType(MachineType type);
 
 }  // namespace internal