Remove signature classes from the VM.

runtime/vm/stub_code_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 1847 matching lines @@
   // R3: instance class id.
   // R4: instance type arguments (null if none), used only if n > 1.
   __ LoadFieldFromOffset(R2, R2, SubtypeTestCache::cache_offset());
   __ AddImmediate(R2, R2, Array::data_offset() - kHeapObjectTag);
 
   Label loop, found, not_found, next_iteration;
   // R2: entry start.
   // R3: instance class id.
   // R4: instance type arguments.
   __ SmiTag(R3);
+  __ CompareImmediate(R3, Smi::RawValue(kClosureCid));
+  __ b(&loop, NE);
+  __ LoadFieldFromOffset(R3, R0, Closure::function_offset());
+  // R3: instance class id as Smi or function.
   __ Bind(&loop);
   __ LoadFromOffset(
-      R5, R2, kWordSize * SubtypeTestCache::kInstanceClassId);
+      R5, R2, kWordSize * SubtypeTestCache::kInstanceClassIdOrFunction);
   __ CompareObject(R5, Object::null_object());
   __ b(&not_found, EQ);
   __ CompareRegisters(R5, R3);
   if (n == 1) {
     __ b(&found, EQ);
   } else {
     __ b(&next_iteration, NE);
     __ LoadFromOffset(
         R5, R2, kWordSize * SubtypeTestCache::kInstanceTypeArguments);
     __ CompareRegisters(R5, R4);
@@ skipping 308 matching lines @@
   __ Bind(&miss);
   __ LoadIsolate(R2);
   __ ldr(CODE_REG, Address(R2, Isolate::ic_miss_code_offset()));
   __ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset()));
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64