reduce always-true/false conditions (switch, loop, if)

[PaulRitter]

logic to detect these will be added with #978. after that its only a question of omitting the condition & jump emits

[TheTyrant25]

#978 was closed and not merged. should this be closed?

[ike709]

Why would we close an issue because of a dead PR?

[TheTyrant25]

idk i thought it was related