r197832 - Move the TargetMachine instance into EmitAssemblyHelper

[Rafael Espíndola]

> -  TargetMachine *TM = CreateTargetMachine(UsesCodeGen);
> +  if (!TM)
> +    TM.reset(CreateTargetMachine(UsesCodeGen));
> +

Just a nit I noticed now: this could be "assert(!TM);" instead of if(!TM), no?

Cheers,
Rafael