This patch obsoletes D11685.
Create wrapper methods in the Function class for the OptimizeForSize and MinSize attributes. We want to hide the logic of "or'ing" them together when optimizing just for size (-Os).
Currently, we are not consistent about this and rely on a front-end to always set OptimizeForSize (-Os) if MinSize (-Oz) is on. Thus, there are 18 FIXME changes here that should be added as follow-on patches with regression tests.
This patch is NFC-intended: it just replaces existing direct accesses of the attributes by the equivalent wrapper call.