[tilegx] Support unorder comparison.
[tilegx] Fix compile warning on gcc 4.7.
[tilegx] Handle float point intrinsics in hard-float mode.

  No hard-float support for these intrinsics, need to expand them into
equivalent instruction sequences or lib call.
[tilegx] Support -soft-float.

  We use hard-float by default, but if -soft-float specified, turn to
soft float instead.
[tilegx] Support new hard-float instructions in MC Layer.