`enable' and `disable' identifiers, because some platforms define
in their system headers symbols with global scope that go by those
names.
* breakpoint.h (enum enable_state): Rename from `enum enable'.
Also rename all the enum members to have the "bp_" prefix.
(struct breakpoint): Rename the `enable' member to `enable_state'.
(enum bpdisp): Rename all members to have the "disp_" prefix.
* breakpoint.c: All users of `enum enable' and `enum bpdisp'
changed.
(args_for_catchpoint_enable): Rename the `enable' member to
`enable_p'. All users changed.
* tracepoint.h (enum enable): Remove.
(struct tracepoint): The member `enabled' is now `int enabled_p'.
* tracepoint.c: All users of the `enabled' member changed.
* printcmd.c (struct display): The `status' member is now an int.
* memattr.h (struct mem_region): Rename the `status' member to
`enabled_p'.
(enum enable): Remove.
* memattr.c: Change all users of the `status' member of struct
mem_region to use `enabled_p' instead.
* infcmd.c (run_stack_dummy): Use disp_del instead of del.
* go32-nat.c: Remove the kludgey work-around for conflicts between
<dos.h> and "breakpoint.h".
* tui/tuiSourceWin.c: Use disp_del instead of del.
* tui/tuiSource.c: Use disp_del instead of del.
* tui/tuiDisassem.c: Use disp_del instead of del.
(tuiShowFrameInfo): Don't crash when there is no symbol table
associated with the pc.
* tuiSource.c (_hasBreak): Check for null source file.
* tuiWin.c (tuiRefreshAll): Check for null winList[type].
(_tuiSetFocus): Check for null dataWin.
* tuiGeneralWin.c (refreshAll): Check for null list[type].
