compiler: remove parentHandle from calling convention

This removes the parentHandle argument from the internal calling convention.
It was formerly used to implment coroutines.
Now that coroutines have been removed, it is no longer necessary.

transform/interrupt.go

@@ -27,7 +27,6 @@ func LowerInterrupts(mod llvm.Module) []error {
 	var errs []error
 
 	ctx := mod.Context()
-	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
 	builder := ctx.NewBuilder()
 	defer builder.Dispose()
 
@@ -95,7 +94,6 @@ func LowerInterrupts(mod llvm.Module) []error {
 				builder.CreateCall(funcPtr, []llvm.Value{
 					num,
 					context,
-					llvm.Undef(i8ptrType),
 				}, "")
 			}
 			call.EraseFromParentAsInstruction()