tcg-ia64: Simplify brcond

tcg-ia64: Simplify brcond

There was a misconception that a stop bit is required between a compare
and the branch that uses the predicate set by the compare.  This lead to
the usage of an extra bundle in which to perform the compare.  The extra
bundle left room for constants to be loaded for use with the compare insn.

If we pack the compare and the branch together in the same bundle, then
there's no longer any room for non-zero constants.  At which point we
can eliminate half the function by not handling them.

Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>