+ /// GetPromotedInteger - Given a processed operand Op which was promoted to a
+ /// larger integer type, this returns the promoted value. The bits of the
+ /// promoted value corresponding to the original type are exactly equal to Op.
+ /// The extra bits contain rubbish, so the promoted value may need to be zero-
+ /// or sign-extended from the original type before it is usable (the helpers
+ /// SExtPromotedInteger and ZExtPromotedInteger can do this for you).
+ /// For example, if Op is an i16 and was promoted to an i32, then this method
+ /// returns an i32, the lower 16 bits of which coincide with Op, and the upper
+ /// 16 bits of which contain rubbish.