Changes to support big endian ARC and consistent testing with both toolchains.

gas/
        * testsuite/gas/all/redef3.d: Replace arc-*-* with arc*-*-*.
        * testsuite/gas/arc/ex_arc700.s: Likewise.
        * testsuite/gas/arc/ld_arc700.s: Likewise.
        * testsuite/gas/arc/warn.s: Likewise.
        * testsuite/gas/lns/lns.exp: Likewise.

ld/
        * Makefile.am (ALL_EMULATION_SOURCES): Added big endian sources.
        * Makefile.in: Regenerated.
        * configure.tgt: Added big endian ARC configurations.
        * emulparams/arcebelf.sh, emulparams/arcebelf_prof.sh,
        emulparams/arceblinux.sh, emulparams/arceblinux_prof.sh: New files.
        * testsuite/ld-discard/extern.d: Replace arc-*-* with arc*-*-*.
        * testsuite/ld-discard/start.d: Likewise.
        * testsuite/ld-discard/static.d: Likewise.
        * testsuite/ld-elf/group1.d: Likewise.
        * testsuite/ld-elf/group8a.d: Likewise.
        * testsuite/ld-elf/group9a.d: Likewise.
        * testsuite/ld-elf/group9b.d: Likewise.
        * testsuite/ld-elf/linkonce2.d: Likewise.
        * testsuite/ld-elf/merge.d: Likewise.
        * testsuite/ld-elf/merge2.d: Likewise.
        * testsuite/ld-elf/orphan-region.d: Likewise.
        * testsuite/ld-elf/orphan.d: Likewise.
        * testsuite/ld-elf/orphan3.d: Likewise.
        * testsuite/ld-elf/pr12851.d: Likewise.
        * testsuite/ld-elf/pr12975.d: Likewise.
        * testsuite/ld-elf/pr13195.d: Likewise.
        * testsuite/ld-elf/pr349.d: Likewise.
        * testsuite/ld-elf/sec64k.exp: Likewise.
        * testsuite/ld-elf/warn1.d: Likewise.
        * testsuite/ld-elf/warn2.d: Likewise.
        * testsuite/ld-elf/warn3.d: Likewise.
        * testsuite/lib/ld-lib.exp: Likewise.