swift234

SIL: Define a switch_oneof instruction.

This instruction encapsulates testing, branching, and destructuring a oneof, as in:

oneof Expr {
  case True
  case False
  case IntLiteral(Int)
  case StringLiteral(String)
}

sil @dispatch_expr : $(Expr) -> () {
entry(%expr : $Expr):
  switch_oneof %expr, \
    case #Expr.True!oneofelt : bb1, \
    case #Expr.False!oneofelt : bb2, \
    case #Expr.IntLiteral!oneofelt : bb3, \
    default bb4
bb1:
  ...
bb2:
  ...
bb3(%int : $Int):
  ...
bb4:
  ...
}

Swift SVN r6329