scripts/gcc: Canadian Cross skip -print-multi-lib log output

Attempting to ${CT_TARGET}-gcc -print-multi-lib will fail

In do_cc_core_backend, for the final compiler in a canadian cross
baremetal, warn that multi-libs cannot be determined

In do_cc_backend, for either final compiler for a canadian cross,
warn that multi-libs cannot be determined

(Plus fixed CT_PREFIX_DIR in do_cc_backend to be ${prefix})

Signed-off-by: "David Holsgrove" <david.holsgrove@xilinx.com>
Message-Id: <CAM=EW8aQDoNx-CkJHjXBoDP4iTDJ8z5hh3=KhO5UTU6rp3Pj=w@mail.gmail.com>
Patchwork-Id: 189053

diff -durN binutils-2.20.1.orig/ld/emulparams/elf_i386.sh binutils-2.20.1/ld/emulparams/elf_i386.sh

--- binutils-2.20.1.orig/ld/emulparams/elf_i386.sh	2009-07-29 16:59:23.000000000 +0200

+++ binutils-2.20.1/ld/emulparams/elf_i386.sh	2010-08-17 19:32:12.000000000 +0200

@@ -13,3 +13,13 @@

 NO_SMALL_DATA=yes

 SEPARATE_GOTPLT=12

 IREL_IN_PLT=

+

+# In Gentoo, we install 32bit libs into /lib32 in an

+# ABI setup with amd64/x86

+case "$target" in

+  x86_64*-linux*)

+    case "$EMULATION_NAME" in

+      *i386*) LIBPATH_SUFFIX=32  ;;

+    esac

+  ;;

+esac