compilation of current git fails

[Werner LEMBERG]

[c8d9edd94d9b1a3e675e811208d9e66eaf9a7daa]

The sequence

```
./autogen.sh
./configure
make
```

aborts with

```
libtool: compile: \
cc -DHAVE_CONFIG_H \
   -I. -I./parsetexi -I. -I./gnulib/lib -I./gnulib/lib \
   -DDATADIR=\"/usr/local/share\" \
   -D_REENTRANT -D_GNU_SOURCE -DPERL_USE_SAFE_PUTENV \
   -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong \
   -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 \
   -fmessage-length=0 -grecord-gcc-switches \
   -O2 -Wall -D_FORTIFY_SOURCE=2 \
   -fstack-protector-strong -funwind-tables \
   -fasynchronous-unwind-tables -fstack-clash-protection \
   -g -Wall -pipe \
   -DVERSION=\"0\" -DXS_VERSION=\"0\" \
   -I/usr/lib/perl5/5.26.1/x86_64-linux-thread-multi/CORE \
   -MT parsetexi/Parsetexi_la-api.lo \
   -MD -MP \
   -MF parsetexi/.deps/Parsetexi_la-api.Tpo \
   -c parsetexi/api.c \
   -fPIC -DPIC \
   -o parsetexi/.libs/Parsetexi_la-api.o
parsetexi/api.c: In function 'reset_parser':
parsetexi/api.c:162:3: warning:
  implicit declaration of function 'debug';
  did you mean 'bug'? [-Wimplicit-function-declaration]
   debug ("!!!!!!!!!!!!!!!! RESETTING THE PARSER !!!!!!!!!!!!!!!!!!!!!");
   ^~~~~
   bug
parsetexi/api.c: In function 'store_source_mark_list':
parsetexi/api.c:465:11: warning:
  enumeration value 'SM_status_none' not handled in switch [-Wswitch]
           switch (s_mark->status)
           ^~~~~~
parsetexi/api.c:478:11: warning:
  enumeration value 'SM_type_none' not handled in switch [-Wswitch]
           switch (s_mark->type)
           ^~~~~~
parsetexi/api.c: In function 'set_debug':
parsetexi/api.c:1037:3: error:
  'debug_output' undeclared (first use in this function)
   debug_output = value;
   ^~~~~~~~~~~~
parsetexi/api.c:1037:3: note:
  each undeclared identifier is reported only once for each function it appears 
in
At top level:
parsetexi/api.c:58:1: warning:
  'find_locales_dir' defined but not used [-Wunused-function]
 find_locales_dir (char *builddir)
 ^~~~~~~~~~~~~~~~
```


    Werner