Minor bug fixes from BSD Net2 gdb:

Minor bug fixes from BSD Net2 gdb:

* blockframe.c (get_prev_frame_info):  If FRAME_CHAIN_COMBINE
returns 0, there is no previous frame.
* breakpoint.c (commands_command):  If !from_tty, don't call
input_from_terminal_p().
* dbxread.c (record_misc_function):  Speed up slightly.
(compare_psymbols):  Ditto.
* infcmd.c (do_registers_info):  Take a second argument to
determine whether to print float registers.  "info registers"
does not do so anymore.  "info all-registers" does, now.
* mips-tdep.c, pyr-tdep.c (xxx_do_registers_info):  Take second
arg and ignore it.
* tm-mips.h, tm-pyr.h (DO_REGISTERS_INFO):  Pass second arg.
* inflow.c (initialize_inflow):  Set tflags_ours correctly.