configury: update to recent versions

Copied from GCC tip.

Fixes #84

config/libtool.m4

@@ -994,23 +994,25 @@ _LT_EOF
         rm -f conftest.err libconftest.a conftest conftest.c
         rm -rf conftest.dSYM
     ])
-    case $host_os in
-    rhapsody* | darwin1.[[012]])
+    # Allow for Darwin 4-7 (macOS 10.0-10.3) although these are not expect to
+    # build without first building modern cctools / linker.
+    case $host_cpu-$host_os in
+    *-rhapsody* | *-darwin1.[[012]])
       _lt_dar_allow_undefined='${wl}-undefined ${wl}suppress' ;;
-    darwin1.*)
+    *-darwin1.*)
       _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress' ;;
-    darwin*) # darwin 5.x on
-      # if running on 10.5 or later, the deployment target defaults
-      # to the OS version, if on x86, and 10.4, the deployment
-      # target defaults to 10.4. Don't you love it?
-      case ${MACOSX_DEPLOYMENT_TARGET-10.0},$host in
-	10.0,*86*-darwin8*|10.0,*-darwin[[91]]*)
-	  _lt_dar_allow_undefined='${wl}-undefined ${wl}dynamic_lookup' ;;
+    *-darwin*)
+      # darwin 5.x (macOS 10.1) onwards we only need to adjust when the
+      # deployment target is forced to an earlier version.
+      case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host in
+	UNSET,*-darwin[[89]]*|UNSET,*-darwin[[12]][[0123456789]]*)
+	  ;;
 	10.[[012]][[,.]]*)
-	  _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress' ;;
-	10.*)
-	  _lt_dar_allow_undefined='${wl}-undefined ${wl}dynamic_lookup' ;;
-      esac
+	  _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
+	  ;;
+	*)
+	  ;;
+     esac
     ;;
   esac
     if test "$lt_cv_apple_cc_single_mod" = "yes"; then
@@ -1033,7 +1035,7 @@ _LT_EOF
 
 # _LT_DARWIN_LINKER_FEATURES
 # --------------------------
-# Checks for linker and compiler features on darwin
+# Checks for linker and compiler features on Darwin / macOS / iOS
 m4_defun([_LT_DARWIN_LINKER_FEATURES],
 [
   m4_require([_LT_REQUIRED_DARWIN_CHECKS])
@@ -2323,16 +2325,6 @@ freebsd* | dragonfly*)
   esac
   ;;
 
-gnu*)
-  version_type=linux
-  need_lib_prefix=no
-  need_version=no
-  library_names_spec='${libname}${release}${shared_ext}$versuffix ${libname}${release}${shared_ext}${major} ${libname}${shared_ext}'
-  soname_spec='${libname}${release}${shared_ext}$major'
-  shlibpath_var=LD_LIBRARY_PATH
-  hardcode_into_libs=yes
-  ;;
-
 haiku*)
   version_type=linux
   need_lib_prefix=no
@@ -2454,7 +2446,7 @@ linux*oldld* | linux*aout* | linux*coff*)
 # project, but have not yet been accepted: they are GCC-local changes
 # for the time being.  (See
 # https://lists.gnu.org/archive/html/libtool-patches/2018-05/msg00000.html)
-linux* | k*bsd*-gnu | kopensolaris*-gnu | uclinuxfdpiceabi)
+linux* | k*bsd*-gnu | kopensolaris*-gnu | gnu* | uclinuxfdpiceabi)
   version_type=linux
   need_lib_prefix=no
   need_version=no
@@ -4878,7 +4870,7 @@ _LT_EOF
       if test "$GCC" = yes && test "$with_gnu_ld" = no; then
 	case $host_cpu in
 	hppa*64*)
-	  _LT_TAGVAR(archive_cmds, $1)='$CC -shared ${wl}+h ${wl}$soname -o $lib $libobjs $deplibs $compiler_flags'
+	  _LT_TAGVAR(archive_cmds, $1)='$CC -shared ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $libobjs $deplibs $compiler_flags'
 	  ;;
 	ia64*)
 	  _LT_TAGVAR(archive_cmds, $1)='$CC -shared -fPIC ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $libobjs $deplibs $compiler_flags'
@@ -4890,7 +4882,7 @@ _LT_EOF
       else
 	case $host_cpu in
 	hppa*64*)
-	  _LT_TAGVAR(archive_cmds, $1)='$CC -b ${wl}+h ${wl}$soname -o $lib $libobjs $deplibs $compiler_flags'
+	  _LT_TAGVAR(archive_cmds, $1)='$CC -b ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $libobjs $deplibs $compiler_flags'
 	  ;;
 	ia64*)
 	  _LT_TAGVAR(archive_cmds, $1)='$CC -b ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $libobjs $deplibs $compiler_flags'
@@ -5867,7 +5859,7 @@ if test "$_lt_caught_CXX_error" != yes; then
           aCC*)
 	    case $host_cpu in
 	      hppa*64*)
-	        _LT_TAGVAR(archive_cmds, $1)='$CC -b ${wl}+h ${wl}$soname -o $lib $predep_objects $libobjs $deplibs $postdep_objects $compiler_flags'
+	        _LT_TAGVAR(archive_cmds, $1)='$CC -b ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $predep_objects $libobjs $deplibs $postdep_objects $compiler_flags'
 	        ;;
 	      ia64*)
 	        _LT_TAGVAR(archive_cmds, $1)='$CC -b ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $predep_objects $libobjs $deplibs $postdep_objects $compiler_flags'
@@ -5891,7 +5883,7 @@ if test "$_lt_caught_CXX_error" != yes; then
 	      if test $with_gnu_ld = no; then
 	        case $host_cpu in
 	          hppa*64*)
-	            _LT_TAGVAR(archive_cmds, $1)='$CC -shared -nostdlib -fPIC ${wl}+h ${wl}$soname -o $lib $predep_objects $libobjs $deplibs $postdep_objects $compiler_flags'
+	            _LT_TAGVAR(archive_cmds, $1)='$CC -shared -nostdlib -fPIC ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $predep_objects $libobjs $deplibs $postdep_objects $compiler_flags'
 	            ;;
 	          ia64*)
 	            _LT_TAGVAR(archive_cmds, $1)='$CC -shared -nostdlib -fPIC ${wl}+h ${wl}$soname ${wl}+nodefaultrpath -o $lib $predep_objects $libobjs $deplibs $postdep_objects $compiler_flags'