[llvm] r277749 - GlobalISel: also add G_TRUNC to IRTranslator.

[Matt Arsenault via llvm-commits]

On 08/18/2016 12:10 PM, Quentin Colombet via llvm-commits wrote:
> Hi Tim,
>
> We were discussing this offline and came to the conclusion that G_TRUNC is a special case of G_EXTRACT.
> In other words, we wouldn’t need that instruction.
>
> I understand that for readability that may not be ideal and enum value are cheap, but still I’d like your thoughts on this.
>
> Cheers,
> -Quentin

This would be good for us. We currently have to deal with a lot of DAG 
combines switching between trunc and vector extracts

-Matt