Continued from http://reviews.llvm.org/D5097
This patch introduces a natural-vector-cast DAG operation which does not generate REV instructions in big-endian mode (unlike ISD:BITCAST).
Currently the patch only fixes movi, fmov and mvni encoded BUILD_VECTORs. If it looks good, I can expand it to fix bic and orr encoded BUILD_VECTORs as well (which are also broken atm).
Asiri.