Log Message:
gawk: update to 5.3.0.

Changes from 5.2.x to 5.3.0
---------------------------

1. Infrastructure changes: Removed the use of libsigsegv. The
   value-add was never very much and it caused problems in some
   environments.

2. In keeping with new features in BWK awk, gawk now has built-in
   CSV file parsing. The behavior is intended to be identical to
   that of the "One True AWK" when --csv is applied. See the
   manual for details.

3. Also in keeping with BWK awk, gawk now supports a new \u escape
   sequence. This should be followed by 1-8 hexadecimal digits. The
   given code point is converted to its corresponding multibyte encoding
   for storage inside gawk. See the manual.

4. If PROCINFO["BUFFERPIPE"] exists, then pipe output is buffered.
   You can also use PROCINFO["command", "BUFFERPIPE"]. See \ 
the manual
   for details.

5. Because of the additional `do_csv' variable in the API, which breaks
   binary compatibility, the API major version was updated to 4 and
   the minor version was reset to zero.  The API remains source code
   compatible; that is, existing extensions should only require recompilation.

6. The manual now requires Texinfo 7.1 and its texinfo.tex for formatting.
   As a result, we no longer need to pre-process it, removing the need
   for gawktexi.in and leaving just gawk.texi.

7. And of course, there have been several minor code cleanups and bug fixes.
   See the ChangeLog for details.

Changes from 5.2.2 to 5.2.x
---------------------------

1. The readdir extension has been updated with additonal code and
   features, see the manual or its man page. As a result, the
   readdir_test.c extension has been removed.

2. We have a new translation: Ukranian.

3. Several subtle issues related to null regexp matches around
   multibyte characters have been fixed.