[PATCH] Canonicalize addrspacecast between different pointer types.

[Michele Scandale]

  I would like to better understand the motivation of this patch: what are the benefit obtained doing a split between the change of address space and the pointer type within the new address space?
  Being a bitcast just a reintepretation of the input value (no change in the bits) this behavior has been included in the addrspacecast instruction (nobody reported any objection on this).

  Thanks in advance.

http://llvm-reviews.chandlerc.com/D2186