dead case field accessor call should be eliminated #6193
Description
while refining my fix for #5739, I discovered case field accessors are not considered pure -- or so it seems...
shouldn't the body of emptyMethod be completely empty when compiled with -optimize?
case class Foo(bla: Int, blaa: String)
class Test {
val f = Foo(1, "1")
// when compiled with -optimize, this method's body should be empty
// however, both calls to the accessors survive (though they are not stored in local variables)
def emptyMethod = {
val x = f.bla // should be considered pure and be eliminated
val y = f.blaa
}
}