Fix PcDescriptor iteratot to never return a pointer to a memory location since the data can move wi…

runtime/vm/code_descriptors_test.cc

 // Copyright (c) 2012, 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 "platform/assert.h"
 #include "vm/globals.h"
 
 #include "vm/ast.h"
 #include "vm/assembler.h"
 #include "vm/code_descriptors.h"
@@ skipping 241 matching lines @@
   stack_bitmap->Set(2, false);  // var k.
   stack_bitmap->Set(3, true);  // var s2.
   stack_bitmap->Set(4, true);  // var s3.
   const Code& code = Code::Handle(function_foo.unoptimized_code());
   // Search for the pc of the call to 'func'.
   const PcDescriptors& descriptors =
       PcDescriptors::Handle(code.pc_descriptors());
   int call_count = 0;
   PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kUnoptStaticCall);
   while (iter.HasNext()) {
-    const RawPcDescriptors::PcDescriptorRec& rec = iter.Next();
-    stackmap_table_builder->AddEntry(rec.pc() - code.EntryPoint(),
+    const uword pc = iter.NextPc();
+    stackmap_table_builder->AddEntry(pc - code.EntryPoint(),
                                      stack_bitmap,
                                      0);
     ++call_count;
   }
   // We can't easily check that we put the stackmap at the correct pc, but
   // we did if there was exactly one call seen.
   EXPECT(call_count == 1);
   const Array& stack_maps =
       Array::Handle(stackmap_table_builder->FinalizeStackmaps(code));
   code.set_stackmaps(stack_maps);
 
   // Now invoke 'A.moo' and it will trigger a GC when the native function
   // is called, this should then cause the stack map of function 'A.foo'
   // to be traversed and the appropriate objects visited.
   const Object& result = Object::Handle(
       DartEntry::InvokeFunction(function_foo, Object::empty_array()));
   EXPECT(!result.IsError());
 }
 
 }  // namespace dart