Stop using shared-ld wrapper script under Mac

We don't need to cater for gcc < 3.1 any longer and can just use
-single_module option unconditionally.

This is simpler and avoids spurious errors about "unknown option" when
using -fsanitize=xxx in LDFLAGS from the script.

configure

@@ -39399,161 +39399,11 @@ $as_echo "$bakefile_cv_prog_makeisgnu" >&6; }
       ;;
 
       *-*-darwin* )
+        SHARED_LD_MODULE_CC="\${CC} -bundle -single_module -headerpad_max_install_names -o"
+        SHARED_LD_MODULE_CXX="\${CXX} -bundle -single_module -headerpad_max_install_names -o"
 
-D='$'
-cat <<EOF >shared-ld-sh
-#!/bin/sh
-#-----------------------------------------------------------------------------
-#-- Name:        distrib/mac/shared-ld-sh
-#-- Purpose:     Link a mach-o dynamic shared library for Darwin / Mac OS X
-#-- Author:      Gilles Depeyrot
-#-- Copyright:   (c) 2002 Gilles Depeyrot
-#-- Licence:     any use permitted
-#-----------------------------------------------------------------------------
-
-verbose=0
-args=""
-objects=""
-linking_flag="-dynamiclib"
-ldargs="-r -keep_private_externs -nostdlib"
-
-if test "x${D}CXX" = "x"; then
-    CXX="c++"
-fi
-
-while test ${D}# -gt 0; do
-    case ${D}1 in
-
-       -v)
-        verbose=1
-        ;;
-
-       -o|-compatibility_version|-current_version|-framework|-undefined|-install_name)
-        # collect these options and values
-        args="${D}{args} ${D}1 ${D}2"
-        shift
-        ;;
-
-       -arch|-isysroot)
-        # collect these options and values
-        ldargs="${D}{ldargs} ${D}1 ${D}2"
-        shift
-        ;;
-
-       -s|-Wl,*)
-        # collect these load args
-        ldargs="${D}{ldargs} ${D}1"
-        ;;
-
-       -l*|-L*|-flat_namespace|-headerpad_max_install_names)
-        # collect these options
-        args="${D}{args} ${D}1"
-        ;;
-
-       -dynamiclib|-bundle)
-        linking_flag="${D}1"
-        ;;
-
-       -*)
-        echo "shared-ld: unhandled option '${D}1'"
-        exit 1
-        ;;
-
-        *.o | *.a | *.dylib)
-        # collect object files
-        objects="${D}{objects} ${D}1"
-        ;;
-
-        *)
-        echo "shared-ld: unhandled argument '${D}1'"
-        exit 1
-        ;;
-
-    esac
-    shift
-done
-
-status=0
-
-#
-# Link one module containing all the others
-#
-if test ${D}{verbose} = 1; then
-    echo "${D}CXX ${D}{ldargs} ${D}{objects} -o master.${D}${D}.o"
-fi
-${D}CXX ${D}{ldargs} ${D}{objects} -o master.${D}${D}.o
-status=${D}?
-
-#
-# Link the shared library from the single module created, but only if the
-# previous command didn't fail:
-#
-if test ${D}{status} = 0; then
-    if test ${D}{verbose} = 1; then
-        echo "${D}CXX ${D}{linking_flag} master.${D}${D}.o ${D}{args}"
-    fi
-    ${D}CXX ${D}{linking_flag} master.${D}${D}.o ${D}{args}
-    status=${D}?
-fi
-
-#
-# Remove intermediate module
-#
-rm -f master.${D}${D}.o
-
-exit ${D}status
-EOF
-
-        chmod +x shared-ld-sh
-
-        SHARED_LD_MODULE_CC="`pwd`/shared-ld-sh -bundle -headerpad_max_install_names -o"
-        SHARED_LD_MODULE_CXX="CXX=\"\$(CXX)\" $SHARED_LD_MODULE_CC"
-
-
-                                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gcc 3.1 or later" >&5
-$as_echo_n "checking for gcc 3.1 or later... " >&6; }
-if ${bakefile_cv_gcc31+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-
-           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-                   #if (__GNUC__ < 3) || \
-                       ((__GNUC__ == 3) && (__GNUC_MINOR__ < 1))
-                       This is old gcc
-                   #endif
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-
-                   bakefile_cv_gcc31=yes
-
-else
-
-                   bakefile_cv_gcc31=no
-
-
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $bakefile_cv_gcc31" >&5
-$as_echo "$bakefile_cv_gcc31" >&6; }
-        if test "$bakefile_cv_gcc31" = "no"; then
-                        SHARED_LD_CC="`pwd`/shared-ld-sh -dynamiclib -headerpad_max_install_names -o"
-            SHARED_LD_CXX="$SHARED_LD_CC"
-        else
-                        SHARED_LD_CC="\${CC} -dynamiclib -single_module -headerpad_max_install_names -o"
-            SHARED_LD_CXX="\${CXX} -dynamiclib -single_module -headerpad_max_install_names -o"
-        fi
+        SHARED_LD_CC="\${CC} -dynamiclib -single_module -headerpad_max_install_names -o"
+        SHARED_LD_CXX="\${CXX} -dynamiclib -single_module -headerpad_max_install_names -o"
 
         if test "x$GCC" = "xyes"; then
             PIC_FLAG="-dynamic -fPIC"