configure.target aix pthread test

[David Edelsohn]

	When configure.host and configure.target were broken out of
configure.in, the extra set of brackets around the AIX release numbers and
version numbers were not removed.  Those extra brackets were needed
because creating configure from configure.in strips a set of brackets, but
configure.target is used directly.

	This fixes libstdc++-v3 configure recognizing pthread multilibs
and configuring accordingly.

David

        * configure.target (aix4*): Remove extra set of brackets.

Index: configure.target
===================================================================
RCS file: /cvs/gcc/egcs/libstdc++-v3/configure.target,v
retrieving revision 1.13
diff -c -p -r1.13 configure.target
*** configure.target	2001/01/23 20:58:23	1.13
--- configure.target	2001/02/08 19:51:37
*************** esac
*** 67,73 ****
  # THIS TABLE IS SORTED.  KEEP IT THAT WAY.
  
  case "${target_os}" in
!   aix4.[[3456789]]* | aix[[56789]]*)
      os_include_dir="config/os/aix"
      case "$CXX" in
        *pthread*)
--- 67,73 ----
  # THIS TABLE IS SORTED.  KEEP IT THAT WAY.
  
  case "${target_os}" in
!   aix4.[3456789]* | aix[56789]*)
      os_include_dir="config/os/aix"
      case "$CXX" in
        *pthread*)