Remove unused variables

	* command.c (break_command): Remove unused variables.
	* tracepoint.c (tracepoint_do_action): Likewise.
Use mmap instead of mprotect

	* gdb.c (initialize_gdb_config): Use mmap instead of mproect to
	allocate tracebuffers.
Add field 'warp'.

	* gdb.c (struct trace_buffer_control) <wrap>: New field.