complibs/ppl: update GMP location configuration argument for PPL v0.11 and later

'configure' for PPL 0.11 (and later) needs "--with-gmp-prefix" to
provide the location of the GMP toolkit; the previous switches were
"--with-libgmp-prefix" and "--with-libgmpxx-prefix".

The upstream log message is:

commit 08dfb6fea094f8c5a533575a3ea2095edce99a6d
Author: Roberto Bagnara <bagnara@cs.unipr.it>
Date: Sun Jul 12 21:39:46 2009 +0200

New configure option --with-gmp-prefix supersedes the (now removed)
options --with-libgmp-prefix and --with-libgmpxx-prefix.

Link: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=08dfb6fea094f8c5a533575a3ea2095edce99a6d

Since PPL's 'configure' ignores unknown switches, we use all three so we
don't have to conditionalize the ppl.sh build script itself.

Signed-Off-By: Anthony Foiani <anthony.foiani@gmail.com>
(transplanted from 4f0c4fb572e2862c24b28e8d27ce7e9cb9adba65)

 # Wrapper to build the debug facilities

 # List all debug facilities, and parse their scripts

 CT_DEBUG_FACILITY_LIST=

 for f in "${CT_LIB_DIR}/scripts/build/debug/"*.sh; do

     _f="$(basename "${f}" .sh)"

     _f="${_f#???-}"

     __f="CT_DEBUG_${_f}"

     if [ "${!__f}" = "y" ]; then

         CT_DoLog DEBUG "Enabling debug '${_f}'"

         . "${f}"

         CT_DEBUG_FACILITY_LIST="${CT_DEBUG_FACILITY_LIST} ${_f}"

     else

         CT_DoLog DEBUG "Disabling debug '${_f}'"

     fi

 done

 # Download the debug facilities

 do_debug_get() {

     for f in ${CT_DEBUG_FACILITY_LIST}; do

         do_debug_${f}_get

     done

 }

 # Extract and patch the debug facilities

 do_debug_extract() {

     for f in ${CT_DEBUG_FACILITY_LIST}; do

         do_debug_${f}_extract

     done

 }

 # Build the debug facilities

 do_debug() {

     for f in ${CT_DEBUG_FACILITY_LIST}; do

         do_debug_${f}_build

     done

 }