Replace intptr_t with TokenDescriptor

runtime/vm/stack_frame.cc

Index: runtime/vm/stack_frame.cc
diff --git a/runtime/vm/stack_frame.cc b/runtime/vm/stack_frame.cc
index 65f7c3ba61346ba298351dd1bc97ad9d07852f9a..fb3d8d858cc0358169d7f1746ad3bcff87891e0d 100644
--- a/runtime/vm/stack_frame.cc
+++ b/runtime/vm/stack_frame.cc
@@ -240,10 +240,10 @@ bool StackFrame::FindExceptionHandler(Thread* thread,
 }
 
 
-intptr_t StackFrame::GetTokenPos() const {
+TokenPosition StackFrame::GetTokenPos() const {
   const Code& code = Code::Handle(LookupDartCode());
   if (code.IsNull()) {
-    return -1;  // Stub frames do not have token_pos.
+    return TokenPosition::kNoSource;  // Stub frames do not have token_pos.
   }
   uword pc_offset = pc() - code.EntryPoint();
   const PcDescriptors& descriptors =
@@ -252,10 +252,10 @@ intptr_t StackFrame::GetTokenPos() const {
   PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
   while (iter.MoveNext()) {
     if (iter.PcOffset() == pc_offset) {
-      return iter.TokenPos();
+      return TokenPosition(iter.TokenPos());
     }
   }
-  return -1;
+  return TokenPosition::kNoSource;
 }