gdb: add frame_id::user_created_p

Later in this series, we'll need to differentiate frame ids for regular
frames (obtained from the target state and unwinding from it) vs frame
ids for user-created frames (created with create_new_frame).  Add the
frame_id::user_created_p field to indicate a frame is user-created, and
set it in create_new_frame.

The field is otherwise not used yet, so not changes in behavior are
expected.

Change-Id: I60de3ce581ed01bf0fddb30dff9bd932840120c3
Reviewed-By: Bruno Larsen <[email protected]>

gdb/frame-id.h

@@ -99,6 +99,10 @@ struct frame_id
   unsigned int code_addr_p : 1;
   unsigned int special_addr_p : 1;
 
+  /* True if this frame was created from addresses given by the user (see
+     create_new_frame) rather than through unwinding.  */
+  unsigned int user_created_p : 1;
+
   /* It is non-zero for a frame made up by GDB without stack data
      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
      Caller of inlined function will have it zero, each more inner called frame

gdb/frame.c

@@ -1953,6 +1953,7 @@ create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
 
   fi->this_id.p = frame_id_status::COMPUTED;
   fi->this_id.value = frame_id_build (addr, pc);
+  fi->this_id.value.user_created_p = 1;
 
   frame_debug_printf ("  -> %s", fi->to_string ().c_str ());