Remove some FIXME comments from DAP

I recently added a 'dap' component to bugzilla, and I filed a few bugs
there.  This patch removes the corresponding FIXME comments.

A few such comments still exist.  In at least one case, I have a fix
I'll be submitting eventually; in others I think I need to do a bit of
investigation to properly file a bug report.

gdb/python/lib/gdb/dap/bt.py

@@ -46,7 +46,6 @@ def _backtrace(thread_id, levels, startFrame):
     set_thread(thread_id)
     frames = []
     current_number = 0
-    # FIXME could invoke frame filters here.
     try:
         current_frame = gdb.newest_frame()
     except gdb.error:

gdb/python/lib/gdb/dap/evaluate.py

@@ -51,7 +51,6 @@ def _repl(command, frame_id):
     }
 
 
-# FIXME 'format' & hex
 # FIXME supportsVariableType handling
 @request("evaluate")
 def eval_request(*, expression, frameId=None, context="variables", **args):
@@ -74,7 +73,6 @@ def _variables(ref, start, count):
 @request("variables")
 # Note that we ignore the 'filter' field.  That seems to be
 # specific to javascript.
-# FIXME: implement format
 def variables(*, variablesReference, start=0, count=0, **args):
     result = send_gdb_with_response(
         lambda: _variables(variablesReference, start, count)

gdb/python/lib/gdb/dap/events.py

@@ -140,13 +140,10 @@ def _on_stop(event):
     global _expected_stop
     obj = {
         "threadId": gdb.selected_thread().global_num,
-        # FIXME we don't support non-stop for now.
         "allThreadsStopped": True,
     }
     if isinstance(event, gdb.BreakpointEvent):
         # Ignore the expected stop, we hit a breakpoint instead.
-        # FIXME differentiate between 'breakpoint', 'function breakpoint',
-        # 'data breakpoint' and 'instruction breakpoint' here.
         _expected_stop = StopKinds.BREAKPOINT
         obj["hitBreakpointIds"] = [x.number for x in event.breakpoints]
     elif _expected_stop is None:

gdb/python/lib/gdb/dap/next.py

@@ -47,5 +47,4 @@ def stepIn(*, threadId, granularity="statement", **args):
 @request("continue")
 def continue_request(**args):
     send_gdb(ExecutionInvoker("continue", None))
-    # FIXME Just ignore threadId for the time being, and assume all-stop.
     return {"allThreadsContinued": True}