Fix broken configure test compromised by LTO

diff --git a/acinclude.m4 b/acinclude.m4
index c35e07f..d052407 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -2885,7 +2885,7 @@ cat >conftest.c <<\EOF
   { '\376', '\334', '\272', '\230', '\166', '\124', '\062', '\020' },
 };]
 EOF
-gmp_compile="$CC $CFLAGS $CPPFLAGS -c conftest.c >&AC_FD_CC 2>&1"
+gmp_compile="$CC $CFLAGS $CPPFLAGS -ffat-lto-objects -c conftest.c >&AC_FD_CC 2>&1"
 if AC_TRY_EVAL(gmp_compile); then
 cat >conftest.awk <<\EOF
 [
diff --git a/configure b/configure
index 0e47b65..7e66697 100755
--- a/configure
+++ b/configure
@@ -23330,7 +23330,7 @@ struct {
   { '\376', '\334', '\272', '\230', '\166', '\124', '\062', '\020' },
 };
 EOF
-gmp_compile="$CC $CFLAGS $CPPFLAGS -c conftest.c >&5 2>&1"
+gmp_compile="$CC $CFLAGS $CPPFLAGS -ffat-lto-objects -c conftest.c >&5 2>&1"
 if { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$gmp_compile\""; } >&5
   (eval $gmp_compile) 2>&5
   ac_status=$?