arch: allow adding a suffix to the arch-part of a tuple

For some architectures, it is legit to have an alternate value in the
'architecture' part of the tuple. For example:
armv5te-*
armv7a8-*

Besides, some packages expect the tuple to reflect the arch variant
(eg. openMPI) to detect the variant's capabilities (eg. atomic
primitives).

This patch adds an option for the user to specify a suffix to be added
to the arch-part of the tuple.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Message-ID: <20130120225822.GS6838@1wt.eu>
Patch-Id: 213994
[yann.morin.1998@free.fr: make it a suffix, not an override]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 # Compute MIPS-specific values

 CT_DoArchTupleValues() {

     local _64

     # The architecture part of the tuple

     if [ "${CT_ARCH_64}" = "y" ]; then

         _64="64"

     fi

     CT_TARGET_ARCH="${CT_ARCH}${_64}${CT_ARCH_SUFFIX:-${target_endian_el}}"

     # Override CFLAGS for endianness:

     case "${CT_ARCH_ENDIAN}" in

         big)    CT_ARCH_ENDIAN_CFLAG="-EB";;

         little) CT_ARCH_ENDIAN_CFLAG="-EL";;

     esac

     # Override ABI flags

     CT_ARCH_ABI_CFLAG="-mabi=${CT_ARCH_mips_ABI}"

     CT_ARCH_WITH_ABI="--with-abi=${CT_ARCH_mips_ABI}"

 }