Clarify the copy semantics of continuations (#816)

executable_semantics/testdata/experimental_continuation8.carbon

@@ -1,27 +0,0 @@
-// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
-// Exceptions. See /LICENSE for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-
-package ExecutableSemanticsTest api;
-
-// Test the way in which copying of continuations interacts with data
-// on the stack such as the variable `x`. In this example the copy
-// happens before the variable `x` is created, so each continuation
-// creates a different `x`.
-
-var y: i32 = 0;
-
-fn main() -> i32 {
-  __continuation k1 {
-    var x: i32 = 0;
-    x = x + 1;
-    __await;
-    y = x;
-  }
-  var k2: __Continuation = k1;
-  __run k1;
-  __run k2;
-  __run k1;
-  __run k2;
-  return y;
-}

executable_semantics/testdata/experimental_continuation8.golden

@@ -1 +0,0 @@
-result: 1