swift234

SIL code motion: consider block arguments when sinking code from predecessors.
Example:

bb1:
  strong_retain %1
  br bb3(%1)
bb2:
  strong_retain %2
  br bb3(%2)
bb3(%3):
  ...

The strong_retain is moved to bb3 with the operand %3.
This opens more opportunities to remove retain-release pairs.



Swift SVN r29356