JS backend: move patternMatching tests to expression/when

js/js.translator/testData/expression/when/cases/doWhileWithOneStmWhen.kt

@@ -0,0 +1,15 @@
+package foo
+
+
+fun box(): Boolean {
+    var result = false
+    var i = 1
+    do
+        when (i) {
+            1 ->    result = true
+            else -> result = false
+        }
+    while (i==0)
+    return result;
+}
+