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)

 diff -dur binutils-2.17.old/ld/emultempl/elf32.em binutils-2.17/ld/emultempl/elf32.em

 --- binutils-2.17.old/ld/emultempl/elf32.em	2006-06-12 15:05:04.000000000 +0200

 +++ binutils-2.17/ld/emultempl/elf32.em	2007-05-01 18:26:13.000000000 +0200

 @@ -970,6 +970,8 @@

  	      && command_line.rpath == NULL)

  	    {

  	      lib_path = (const char *) getenv ("LD_RUN_PATH");

 +	      if ((lib_path) && (strlen (lib_path) == 0))

 +		  lib_path = NULL;

  	      if (gld${EMULATION_NAME}_search_needed (lib_path, &n,

  						      force))

  		break;

 @@ -1154,6 +1156,8 @@

    rpath = command_line.rpath;

    if (rpath == NULL)

      rpath = (const char *) getenv ("LD_RUN_PATH");

 +  if ((rpath) && (strlen (rpath) == 0))

 +      rpath = NULL;

    if (! (bfd_elf_size_dynamic_sections

  	 (output_bfd, command_line.soname, rpath,

  	  command_line.filter_shlib,