Rematerialize ALU+IMM operations on ARM (bug 555255 r=jbramley+)
Rematerialize ALU+IMM operations on ARM (bug 555255 r=jbramley+)

The ARM backend already supported single-instruction folding of immediates into
add/sub/and/or/xor instructions.  This patch enables the same instructions to
be rematerialized without spilling them.

pnkfelix/tamarin-redux,pnkfelix/tamarin-redux,pnkfelix/tamarin-redux,pnkfelix/tamarin-redux,pfgenyun/tamarin-redux,pnkfelix/tamarin-redux,pfgenyun/tamarin-redux,pnkfelix/tamarin-redux,pfgenyun/tamarin-redux,pfgenyun/tamarin-redux,pfgenyun/tamarin-redux,pfgenyun/tamarin-redux,pfgenyun/tamarin-redux,pfgenyun/tamarin-redux,pnkfelix/tamarin-redux