Fix crashers in do/while and while(await(..))

The new tree shapes handled for do/while look like:

    // type checked
    async({
      val b = false;
      doWhile$1(){
        await(());
        if (b)
          doWhile$1()
        else
          ()
      };
      ()
    })

We had to change ExprBuilder to create states for the if/else
that concludes the doWhile body, and also loosen the assertion
that the label jump must be the last thing we see.

We also have to look for more than just `containsAwait` when
deciding whether an `If` needs to be transformed into states;
it might also contain a jump to the enclosing label that is on
the other side of an `await`, and hence needs to be a state
transition instead.

1 files changed, 40 insertions, 0 deletions

diff --git a/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala b/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala
index 4b3c2aa..76e6b1e 100644
--- a/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala
+++ b/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala
@@ -76,4 +76,44 @@ class WhileSpec {
     }
     result mustBe ()
   }
+
+  @Test def doWhile() {
+    import AsyncId._
+    val result = async {
+      var b = 0
+      var x = ""
+      await(do {
+        x += "1"
+        x += await("2")
+        x += "3"
+        b += await(1)
+      } while (b < 2))
+      await(x)
+    }
+    result mustBe "123123"
+  }
+
+  @Test def whileAwaitCondition() {
+    import AsyncId._
+    val result = async {
+      var b = true
+      while(await(b)) {
+        b = false
+      }
+      await(b)
+    }
+    result mustBe false
+  }
+
+  @Test def doWhileAwaitCondition() {
+    import AsyncId._
+    val result = async {
+      var b = true
+      do {
+        b = false
+      } while(await(b))
+      b
+    }
+    result mustBe false
+  }
 }