[compiler] Simplify OperationTyper::ToPrimitive.

R=jarin@chromium.org

Bug: 
Change-Id: I9adf207491a146459d676342c0b7bdf0c399e440
Reviewed-on: https://chromium-review.googlesource.com/758260Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49217}

src/compiler/operation-typer.cc

@@ -1024,7 +1024,7 @@ Type* OperationTyper::SpeculativeToNumber(Type* type) {
 }
 
 Type* OperationTyper::ToPrimitive(Type* type) {
-  if (type->Is(Type::Primitive()) && !type->Maybe(Type::Receiver())) {
+  if (type->Is(Type::Primitive())) {
     return type;
   }
   return Type::Primitive();