Revert of Provide a tagged allocation top pointer.

src/crankshaft/arm/lithium-codegen-arm.cc

Index: src/crankshaft/arm/lithium-codegen-arm.cc
diff --git a/src/crankshaft/arm/lithium-codegen-arm.cc b/src/crankshaft/arm/lithium-codegen-arm.cc
index 119f3fe57b8c742b4b292c6d110bce4614cb8a60..e6d2182a77208fa7d122b083c58ead2c5364a5e4 100644
--- a/src/crankshaft/arm/lithium-codegen-arm.cc
+++ b/src/crankshaft/arm/lithium-codegen-arm.cc
@@ -5172,8 +5172,10 @@
     ExternalReference allocation_top =
         AllocationUtils::GetAllocationTopReference(isolate(), allocation_flags);
     Register top_address = scratch0();
+    __ sub(r0, r0, Operand(kHeapObjectTag));
     __ mov(top_address, Operand(allocation_top));
     __ str(r0, MemOperand(top_address));
+    __ add(r0, r0, Operand(kHeapObjectTag));
   }
 }