[PATCH] [AArch64 NEON] Fix wrong imm used in BIC instruction.

[Kevin Qin]

  Hi Tim,

  Thanks for your review. This part of codes was implemented by Ana long time ago. I believe there is no such bitconvert node in DAG which holds same value type in its operand and result. I guess for pattern matcher, its a dumb node and just skip it to match next. So from functionality perspective, it's OK to insert this kind of bitconvert everythere and any times. But to keep code readable and more efficiency, I suggest don't use this dumb node. So I removed it in this patch.  Do you agree?

http://llvm-reviews.chandlerc.com/D2500