Use Gnulib libgmp module

Instead of doing GMP by hand, use the Gnulib libgmp module.
* .gitignore: Add lib/gmp.h.
* admin/merge-gnulib (GNULIB_MODULES): Add libgmp.
* configure.ac (GMP_LIB, GMP_OBJ): Remove.  Gnulib uses the name
LIB_GMP, so all uses changed.  All uses of GMP_OBJ removed.
(HAVE_GMP): Set this from Gnulib’s variables.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/mini-gmp-gnulib.c, lib/mini-gmp.c, lib/mini-gmp.h, m4/libgmp.m4:
New files, copied from Gnulib.
* src/bignum.h, test/data/emacs-module/mod-test.c:
Include gmp.h unconditionally.
* src/mini-gmp-emacs.c, src/mini-gmp.c, src/mini-gmp.h:
Remove.  This moves these files from src to lib, and
updates them to the current GMP version.
* test/Makefile.in (GMP_H): New macro.
($(test_module)): Use it to decide whether to compile
mini-gmp-gnulib.c too.

1 files changed, 37 insertions, 0 deletions

diff --git a/lib/mini-gmp-gnulib.c b/lib/mini-gmp-gnulib.c
new file mode 100644
index 00000000000..5019be5d52a
--- /dev/null
+++ b/lib/mini-gmp-gnulib.c
@@ -0,0 +1,37 @@
+/* Tailor mini-gmp.c for Gnulib-using applications.
+
+   Copyright 2018-2020 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <stddef.h>
+#include <stdio.h>
+
+#include "mini-gmp.h"
+
+/* Pacify GCC -Wsuggest-attribute=const, malloc, pure.  */
+#if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=const"
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=malloc"
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
+#endif
+
+/* Pacify GCC -Wunused-variable for variables used only in 'assert' calls.  */
+#if defined NDEBUG && 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
+# pragma GCC diagnostic ignored "-Wunused-variable"
+#endif
+
+#include "mini-gmp.c"