Implement frame apply [all | COUNT | -COUNT | level LEVEL... ] [FLAG]... COMMAND.

Implement frame apply [all | COUNT | -COUNT | level LEVEL... ] [FLAG]... COMMAND.

Implement frame apply [all | COUNT | -COUNT | level LEVEL... ] [FLAG]... COMMAND.
Also implement the command 'faas COMMAND', a shortcut for
'frame apply all -s COMMAND'.

The syntax of 'frame apply' to specify some innermost or outermost
frames is similar to 'backtrace' command, using COUNT or -COUNT.

To apply a COMMAND to a more specific set of frames, the following
new command and syntax can be used:
frame apply level LEVEL... [FLAG]... COMMAND
where LEVEL is one or more frame levels or range of frame levels.

The new command 'frame apply' allows to apply a COMMAND to a number of frames,
or to all frames, or to a set of frames.
The optional [FLAG]... arguments allow to control what output to produce
and how to handle errors raised when applying COMMAND to a frame.

Some example usages for this new command:
   frame apply all info frame
      Produce info frame for all frames.
   frame apply all p $sp
      For each frame, print the location, followed by the frame sp.
   frame apply all -q p $sp
      Same as before, but -q flag (q = quiet) indicates to only print
      the frames sp.
   frame apply all p some_local_var_somewhere
      Print some_local_var_somewhere in all frames. 'frame apply'
      will abort as soon as the print command fails.
   frame apply all -c p some_local_var_somewhere
      Same as before, but -c flag (c = continue) means to
      print the error and continue applying command in case the
      print command fails.
   frame apply all -s p some_local_var_somewhere
      Same as before, but -s flag (s = silent) means to
      be silent for frames where the print command fails.
      In other words, this allows to 'search' the frame in which
      some_local_var_somewhere can be printed.
   frame apply all -s -q p some_local_var_somewhere
      Same as before, but does not print the frame info in which
      the variable is found.
   frame apply level 2-4 5 8-10 -s p i = i + 1
      Increments i in the identified frames.

gdb/ChangeLog
2018-07-12  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* stack.c: (trailing_outermost_frame): New function, mostly
	extracted from backtrace_command_1.
	(leading_innermost_frame): New function.
	(backtrace_command_1): Update to call trailing_outermost_frame.
	(frame_apply_command_count): New function.
	(frame_apply_level_command): New function.
	(frame_apply_all_command): New function.
	(frame_apply_command): New function.
	(faas_command): New function.
	(frame_cmd_list): New variable.
	(_initialize_stack): Update to setup the new commands 'frame apply'
	and 'faas'.