* lisp.h (USE_2_TAGS_FOR_INTS): Remove, as it was always defined.
(LISP_INT_TAG, case_Lisp_Int, LISP_STRING_TAG, LISP_INT_TAG_P)
(LISP_INT1_TAG, enum Lisp_Type, XINT, XUINT, make_number):
Simplify under the assumption that USE_2_TAGS_FOR_INTS is defined.
(INTTYPEBITS): New macro, for clarity.
(INTMASK, MOST_POSITIVE_FIXNUM): Use it.
(LISP_INT1_TAG, LISP_STRING_TAG, LISP_INT_TAG_P): Simplify
now that USE_LSB_TAG is always defined.
(TYPEMASK, XINT) [USE_LSB_TAG]: Remove unnecessary cast.
(make_number) [!USE_LSB_TAG]: Use INTMASK; that's simpler.

* src/s/bsd-common.h (BSD4_3):
* src/s/usg5-4-common.h (USG5_4): No longer define; unused.

* admin/CPP-DEFINES, src/s/template.h: Related edits.

* configure.in: Rename --enable-use-lisp-union-type to
--enable-check-lisp-object-type and define CHECK_LISP_OBJECT_TYPE
instead of USE_LISP_UNION_TYPE.

* admin/make-emacs: Rename --union-type to --check-lisp-type.  Define
CHECK_LISP_OBJECT_TYPE insted of USE_LISP_UNION_TYPE.
* admin/CPP-DEFINES (DEBUG_LISP_OBJECT_TYPE): Renamed from
USE_LISP_UNION_TYPE.

* src/lisp.h (Lisp_Object) [CHECK_LISP_OBJECT_TYPE]: Define as struct
instead of union.
(XLI, XIL): Define.
(XHASH, XTYPE, XINT, XUINT, make_number, XSET, XPNTR, XUNTAG): Use
them.
* src/emacs.c (gdb_use_struct): Renamed from gdb_use_union.
* src/.gdbinit: Check gdb_use_struct instead of gdb_use_union.
* src/alloc.c (widen_to_Lisp_Object): Removed.
(mark_memory): Use XIL instead of widen_to_Lisp_Object.
* src/frame.c (delete_frame): Remove outdated comment.
* src/w32fns.c (Fw32_register_hot_key): Use XLI instead of checking
USE_LISP_UNION_TYPE.
(Fw32_unregister_hot_key): Likewise.
(Fw32_toggle_lock_key): Likewise.
* src/w32menu.c (add_menu_item): Likewise.
(w32_menu_display_help): Use XIL instead of checking
USE_LISP_UNION_TYPE.
* src/w32heap.c (allocate_heap): Don't check USE_LISP_UNION_TYPE.
(init_heap): Likewise.
* src/w32term.c (w32_read_socket): Update comment.

* src/s/usg5-4-common.h, src/s/unixware.h:
Remove define/undef of HAVE_SYSV_SIGPAUSE (not used since 2010-05-04).

* admin/CPP-DEFINES: Remove HAVE_SYSV_SIGPAUSE.

This was added in 2012-01 in response to http://debbugs.gnu.org/10552 .
However, this issue had already been fixed in the trunk two years
earlier, by removing POSIX_SIGNALS altogether. Ref:

http://lists.gnu.org/archive/html/emacs-devel/2010-04/msg00002.html

* alloc.c (make_number) [!defined make_number]:
Remove, as lisp.h always defines this now.
(mark_maybe_pointer): Simplify since USE_LSB_TAG is always defined now.
(roundup_size): Verify that it is a power of 2.
* data.c (Fmake_variable_buffer_local, Fmake_local_variable):
* ftfont.c (ftfont_driver): Use LISP_INITIALLY_ZERO.
* lisp.h (USE_LSB_TAG): Allow the builder to compile with
-DUSE_LSB_TAG=0, to override the automatically-selected default.
USE_LSB_TAG now is always defined to be either 0 or 1.
All uses changed.
(union Lisp_Object): Don't worry about WORDS_BIGENDIAN; the
code works fine either way, and efficiency is not a concern here,
as the union type is for debugging, not for production.
(LISP_MAKE_RVALUE, make_number) [USE_LISP_UNION_TYPE]:
Use an inline function on all platforms when using the union type,
since this is simpler and 'static inline' can be used portably
within Emacs now.
(LISP_INITIALLY_ZERO): New macro.
(XFASTINT, XSETFASTINT) [USE_LISP_UNION_TYPE]: Remove.
(XSET) [USE_LISP_UNION_TYPE]: Don't overparenthesize.

* configure.in (HAVE_PROCFS, _STRUCTURED_PROC): New AC_DEFINEs.
(opsysfile): Set specially for sol2-10.

* src/s/gnu-linux.h (HAVE_PROCFS): Move to configure.

* src/s/sol2-10.h: Remove file.

* configure.in (BROKEN_SA_RESTART, USG_SUBTTY_WORKS): New AC_DEFINEs.
(opsysfile): Set specially for hpux11.

* src/s/hpux11.h: Remove file.