Bug 1042244: Make comparison operators always return int32_t; r=nmatsakis
Bug 1042244: Remove return template parameter in SIMD operators; r=nmatsakis
Bug 1042244: Simplify and generalize FuncShuffle; r=nmatsakis
Bug 1042244: Instantiate operators template arguments in users; r=nmatsakis
Bug 1042244: Make FuncWith return the same type as their inputs; r=nmatsakis