swift234

Reapply the cfg trampoline optimization and add another cond_br optimization:

Same target:

 cond_br %0, bb1(%1 : $Int64), bb2(%1 : $Int64)

And trampolines:

bb0(%0 : $Builtin.Int1, %1 : $Int64, %2 : $Int64):
  cond_br %0, bb1(%1 : $Int64), bb2(%2 : $Int64)

bb1(%3 : $Int64):
  br bb3(%3 : $Int64)

bb2(%4 : $Int64):
  br bb3(%4 : $Int64)





Swift SVN r13275