Avoid crash by SIGFPE during plural form expression evaluation.
Libraries (such as libintl and libgettextpo) should not raise signals, because
catching such signals cannot be done in a multithread-safe way.
* gettext-runtime/intl/plural-exp.h (enum eval_status): New enum items
PE_INTDIV, PE_INTOVF.
* gettext-runtime/intl/eval-plural.h (plural_eval_recurse): When a division
argument is zero, return status PE_INTDIV instead of raising SIGFPE.
* gettext-runtime/intl/dcigettext.c (INTDIV0_RAISES_SIGFPE): Remove macro.
Don't include <signal.h>.
* gettext-runtime/intl/configure.ac: Don't invoke gt_INTDIV0.
* gettext-runtime/intl/m4/intdiv0.m4: Remove file.
* gettext-runtime/intl/Makefile.am (ACLOCAL_AMFLAGS): Remove option '-I m4'.
(EXTRA_DIST): Remove m4/intdiv0.m4.
* autogen.sh: When invoking aclocal in gettext-runtime/intl, omit option
'-I m4'.
* gettext-tools/src/msgl-check.c: Don't include <setjmp.h>, <signal.h>.
(plural_expression_histogram): Don't invoke install_sigfpe_handler,
uninstall_sigfpe_handler.
(check_plural_eval): Don't invoke setjmp, install_sigfpe_handler,
uninstall_sigfpe_handler. Remove 'volatile' from array variable.
Produce error message when status PE_INTDIV or PE_INTOVF occurred.
* gettext-tools/src/plural-eval.h: Don't include <setjmp.h>.
(sigjmp_buf, sigsetjmp, siglongjmp): Remove definitions.
(USE_SIGINFO): Remove macro.
(sigfpe_exit, sigfpe_code, install_sigfpe_handler, uninstall_sigfpe_handler):
Remove declarations.
* gettext-tools/src/plural-eval.c: Don't include <signal.h>.
(sigfpe_exit, sigfpe_code): Remove variables.
(sigfpe_handler, install_sigfpe_handler, uninstall_sigfpe_handler): Remove
functions.
* gettext-tools/configure.ac: Don't invoke gt_SIGINFO.
* gettext-tools/m4/siginfo.m4: Remove file.
* gettext-tools/m4/Makefile.am (EXTRA_DIST): Remove it.
