vector-based ICs did not update type feedback counts correctly.

src/arm64/code-stubs-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 3023 matching lines @@
     __ bind(&wrap);
     EmitWrapCase(masm, argc, &cont);
   }
 
   __ bind(&extra_checks_or_miss);
   Label miss;
 
   __ JumpIfRoot(x4, Heap::kmegamorphic_symbolRootIndex, &slow_start);
   __ JumpIfRoot(x4, Heap::kuninitialized_symbolRootIndex, &miss);
 
-  if (!FLAG_trace_ic) {
-    // We are going megamorphic. If the feedback is a JSFunction, it is fine
-    // to handle it here. More complex cases are dealt with in the runtime.
-    __ AssertNotSmi(x4);
-    __ JumpIfNotObjectType(x4, x5, x5, JS_FUNCTION_TYPE, &miss);
-    __ Add(x4, feedback_vector,
-           Operand::UntagSmiAndScale(index, kPointerSizeLog2));
-    __ LoadRoot(x5, Heap::kmegamorphic_symbolRootIndex);
-    __ Str(x5, FieldMemOperand(x4, FixedArray::kHeaderSize));
-    __ B(&slow_start);
-  }
-
   // We are here because tracing is on or we are going monomorphic.
   __ bind(&miss);
   GenerateMiss(masm);
 
   // the slow case
   __ bind(&slow_start);
 
   // Check that the function is really a JavaScript function.
   __ JumpIfSmi(function, &non_function);
 
@@ skipping 1994 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64