Move blackBoxFile() testData to box/ directory

Delete all test methods (and empty test classes), since they'll be
auto-generated

compiler/testData/codegen/box/controlStructures/tryCatchFinallyChain.kt

@@ -0,0 +1,19 @@
+fun box() : String {
+    try {
+    } finally {
+        try {
+            try {
+            } finally {
+                try {
+                } finally {
+                }
+            }
+        } catch (e: Exception) {
+            try {
+            } catch (f: Exception) {
+            } finally {
+            }
+        }
+        return "OK"
+    }
+}