Patch configure to support PowerPC little endian

The earliest libtool release that supports PowerPC little endian
is 2.4.3. Patch configure to enable support for this architecture.

(cherry picked from commit open-mpi/ompi@12c5063d58d3)

Author: nysal

autogen.pl

@@ -7,6 +7,8 @@
 # Copyright (c) 2013-2014 Intel, Inc.  All rights reserved.
 # Copyright (c) 2015      Research Organization for Information Science
 #                         and Technology (RIST). All rights reserved.
+# Copyright (c) 2015      IBM Corporation.  All rights reserved.
+#
 # $COPYRIGHT$
 #
 # Additional copyrights may follow
@@ -980,6 +982,19 @@ sub patch_autotools_output {
     push(@verbose_out, $indent_str . "Patching configure for IBM xlf libtool bug\n");
     $c =~ s/(\$LD -shared \$libobjs \$deplibs \$)compiler_flags( -soname \$soname)/$1linker_flags$2/g;
 
+    #Check if we are using a recent enough libtool that supports PowerPC little endian
+    if(index($c, 'powerpc64le-*linux*)') == -1) {
+        push(@verbose_out, $indent_str . "Patching configure for PowerPC little endian support\n");
+        my $replace_string = "x86_64-*kfreebsd*-gnu|x86_64-*linux*|powerpc*-*linux*|";
+        $c =~ s/x86_64-\*kfreebsd\*-gnu\|x86_64-\*linux\*\|ppc\*-\*linux\*\|powerpc\*-\*linux\*\|/$replace_string/g;
+        $replace_string =
+        "powerpc64le-*linux*)\n\t    LD=\"\${LD-ld} -m elf32lppclinux\"\n\t    ;;\n\t  powerpc64-*linux*)";
+        $c =~ s/ppc64-\*linux\*\|powerpc64-\*linux\*\)/$replace_string/g;
+        $replace_string =
+        "powerpcle-*linux*)\n\t    LD=\"\${LD-ld} -m elf64lppc\"\n\t    ;;\n\t  powerpc-*linux*)";
+        $c =~ s/ppc\*-\*linux\*\|powerpc\*-\*linux\*\)/$replace_string/g;
+    }
+
     # Fix consequence of broken libtool.m4
     # see http://lists.gnu.org/archive/html/bug-libtool/2015-07/msg00002.html and
     # https://github.com/open-mpi/ompi/issues/751