Better inlining of type tests.

runtime/vm/flow_graph_compiler_x64.cc

Index: runtime/vm/flow_graph_compiler_x64.cc
===================================================================
--- runtime/vm/flow_graph_compiler_x64.cc	(revision 33221)
+++ runtime/vm/flow_graph_compiler_x64.cc	(working copy)
@@ -506,20 +506,6 @@
     // type error. A null value is handled prior to executing this inline code.
     return SubtypeTestCache::null();
   }
-  if (TypeCheckAsClassEquality(type)) {
-    const intptr_t type_cid = Class::Handle(type.type_class()).id();
-    const Register kInstanceReg = RAX;
-    __ testq(kInstanceReg, Immediate(kSmiTagMask));
-    if (type_cid == kSmiCid) {
-      __ j(ZERO, is_instance_lbl);
-    } else {
-      __ j(ZERO, is_not_instance_lbl);
-      __ CompareClassId(kInstanceReg, type_cid);
-      __ j(EQUAL, is_instance_lbl);
-    }
-    __ jmp(is_not_instance_lbl);
-    return SubtypeTestCache::null();
-  }
   if (type.IsInstantiated()) {
     const Class& type_class = Class::ZoneHandle(type.type_class());
     // A class equality check is only applicable with a dst type of a