Revert "Use the object class as top in reference type propagation"

failing on the build bot on some targets but not locally. needs more investigation.

This reverts commit 20e6071362b84a9782b633a893c29ebde458205e.

Change-Id: I6965483f569fb862f9bdb66d459b747ded54de71
diff --git a/compiler/optimizing/inliner.cc b/compiler/optimizing/inliner.cc
index 860b199..3efe7c7 100644
--- a/compiler/optimizing/inliner.cc
+++ b/compiler/optimizing/inliner.cc
@@ -109,8 +109,10 @@
     receiver = receiver->InputAt(0);
   }
   ReferenceTypeInfo info = receiver->GetReferenceTypeInfo();
-  DCHECK(info.IsValid()) << "Invalid RTI for " << receiver->DebugName();
-  if (!info.IsExact()) {
+  if (info.IsTop()) {
+    // We have no information on the receiver.
+    return nullptr;
+  } else if (!info.IsExact()) {
     // We currently only support inlining with known receivers.
     // TODO: Remove this check, we should be able to inline final methods
     // on unknown receivers.