While developing jsgo, I noticed that the entire stdlib builds reproducibly apart from image/draw. Only the un-minified code shows the problem.

This switch statement: https://github.com/golang/go/blob/master/src/image/draw/draw.go#L608-L615

... the variables src0$1, src0$2 and src0 are re-arranged.

I'll dig into the compiler code and try to work out what's wrong.