diff --git a/configure b/configure
index ec4ed1f..b173800 100755
--- a/configure
+++ b/configure
@@ -5160,55 +5160,6 @@ else
   NM="$ac_cv_prog_NM"
 fi
 
-
-# We use -std=gnu99 but have explicit checks for some language constructs
-# and GNU extensions since some compilers claim GNU99 support, but don't
-# really support all language extensions. In particular we need
-# Mixed Declarations and Code
-# https://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html
-# Nested Functions
-# https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html
-# Arrays of Variable Length
-# https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gcc with GNU99 support" >&5
-$as_echo_n "checking for gcc with GNU99 support... " >&6; }
-if ${ac_cv_c99+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  old_CFLAGS="$CFLAGS"
-CFLAGS="$CFLAGS -std=gnu99"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-int foo (int a)
-{
-  for (int i = 0; i < a; ++i) if (i % 4) break; int s = a; return s;
-}
-
-double bar (double a, double b)
-{
-  double square (double z) { return z * z; }
-  return square (a) + square (b);
-}
-
-void baz (int n)
-{
-  struct S { int x[n]; };
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_c99=yes
-else
-  ac_cv_c99=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-CFLAGS="$old_CFLAGS"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c99" >&5
-$as_echo "$ac_cv_c99" >&6; }
-if test "x$ac_cv_c99" != xyes; then :
-  as_fn_error $? "gcc with GNU99 support required" "$LINENO" 5
-fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether gcc supports __attribute__((visibility()))" >&5
 $as_echo_n "checking whether gcc supports __attribute__((visibility()))... " >&6; }
 if ${ac_cv_visibility+:} false; then :
@@ -5363,43 +5314,6 @@ if test "$ac_cv_zdefs" = "yes"; then
 	dso_LDFLAGS="$dso_LDFLAGS $ZDEFS_LDFLAGS"
 fi
 
-# We really want build-ids. Warn and force generating them if gcc was
-# configure without --enable-linker-build-id
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler generates build-ids" >&5
-$as_echo_n "checking whether the compiler generates build-ids... " >&6; }
-if ${ac_cv_buildid+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_buildid=yes; $READELF -n conftest$EXEEXT | grep -q NT_GNU_BUILD_ID || ac_cv_buildid=no
-else
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "unexpected compile failure
-See \`config.log' for more details" "$LINENO" 5; }
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_buildid" >&5
-$as_echo "$ac_cv_buildid" >&6; }
-if test "$ac_cv_buildid" = "no"; then
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: compiler doesn't generate build-id by default" >&5
-$as_echo "$as_me: WARNING: compiler doesn't generate build-id by default" >&2;}
-	LDFLAGS="$LDFLAGS -Wl,--build-id"
-fi
-
 ZRELRO_LDFLAGS="-Wl,-z,relro"
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether gcc supports $ZRELRO_LDFLAGS" >&5
 $as_echo_n "checking whether gcc supports $ZRELRO_LDFLAGS... " >&6; }
@@ -5436,47 +5350,6 @@ if test "$ac_cv_zrelro" = "yes"; then
 fi
 
 
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __thread support" >&5
-$as_echo_n "checking for __thread support... " >&6; }
-if ${ac_cv_tls+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  # Use the same flags that we use for our DSOs, so the test is representative.
-# Some old compiler/linker/libc combinations fail some ways and not others.
-save_CFLAGS="$CFLAGS"
-save_LDFLAGS="$LDFLAGS"
-CFLAGS="$fpic_CFLAGS $CFLAGS"
-LDFLAGS="$dso_LDFLAGS $LDFLAGS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <stdlib.h>
-#undef __thread
-static __thread int a; int foo (int b) { return a + b; }
-int
-main ()
-{
-exit (foo (0));
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_tls=yes
-else
-  ac_cv_tls=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-CFLAGS="$save_CFLAGS"
-LDFLAGS="$save_LDFLAGS"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_tls" >&5
-$as_echo "$ac_cv_tls" >&6; }
-if test "x$ac_cv_tls" != xyes; then :
-  as_fn_error $? "__thread support required" "$LINENO" 5
-fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether gcc provides stdatomic.h" >&5
 $as_echo_n "checking whether gcc provides stdatomic.h... " >&6; }
 if ${ac_cv_has_stdatomic+:} false; then :
@@ -7345,74 +7218,6 @@ $as_echo "#define HAVE_FALLTHROUGH 1" >>confdefs.h
 
 fi
 
-saved_LIBS="$LIBS"
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing argp_parse" >&5
-$as_echo_n "checking for library containing argp_parse... " >&6; }
-if ${ac_cv_search_argp_parse+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char argp_parse ();
-int
-main ()
-{
-return argp_parse ();
-  ;
-  return 0;
-}
-_ACEOF
-for ac_lib in '' argp; do
-  if test -z "$ac_lib"; then
-    ac_res="none required"
-  else
-    ac_res=-l$ac_lib
-    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
-  fi
-  if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_argp_parse=$ac_res
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext
-  if ${ac_cv_search_argp_parse+:} false; then :
-  break
-fi
-done
-if ${ac_cv_search_argp_parse+:} false; then :
-
-else
-  ac_cv_search_argp_parse=no
-fi
-rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_argp_parse" >&5
-$as_echo "$ac_cv_search_argp_parse" >&6; }
-ac_res=$ac_cv_search_argp_parse
-if test "$ac_res" != no; then :
-  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
-
-fi
-
-LIBS="$saved_LIBS"
-case "$ac_cv_search_argp_parse" in
-        no) { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "failed to find argp_parse
-See \`config.log' for more details" "$LINENO" 5; } ;;
-        -l*) argp_LDADD="$ac_cv_search_argp_parse" ;;
-        *) argp_LDADD= ;;
-esac
-
-
 saved_LIBS="$LIBS"
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fts_close" >&5
 $as_echo_n "checking for library containing fts_close... " >&6; }
@@ -7481,75 +7286,6 @@ See \`config.log' for more details" "$LINENO" 5; } ;;
 esac
 
 
-saved_LIBS="$LIBS"
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing _obstack_free" >&5
-$as_echo_n "checking for library containing _obstack_free... " >&6; }
-if ${ac_cv_search__obstack_free+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char _obstack_free ();
-int
-main ()
-{
-return _obstack_free ();
-  ;
-  return 0;
-}
-_ACEOF
-for ac_lib in '' obstack; do
-  if test -z "$ac_lib"; then
-    ac_res="none required"
-  else
-    ac_res=-l$ac_lib
-    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
-  fi
-  if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search__obstack_free=$ac_res
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext
-  if ${ac_cv_search__obstack_free+:} false; then :
-  break
-fi
-done
-if ${ac_cv_search__obstack_free+:} false; then :
-
-else
-  ac_cv_search__obstack_free=no
-fi
-rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search__obstack_free" >&5
-$as_echo "$ac_cv_search__obstack_free" >&6; }
-ac_res=$ac_cv_search__obstack_free
-if test "$ac_res" != no; then :
-  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
-
-fi
-
-LIBS="$saved_LIBS"
-case "$ac_cv_search__obstack_free" in
-        no) { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "failed to find _obstack_free
-See \`config.log' for more details" "$LINENO" 5; } ;;
-        -l*) obstack_LIBS="$ac_cv_search__obstack_free" ;;
-        *) obstack_LIBS= ;;
-esac
-
-
-
 ac_config_files="$ac_config_files doc/Makefile"
 
 
