ART: Distinguish Checker lines from comments

In order to prevent tests passing due to lines with hard-to-spot
formatting errors begin ignored, e.g. by forgetting the colon after
"//CHECK", Checker will now require its assertions to start with "///"
or "##", respectivelly for Java and Smali. Such lines will never be
ignored and will fail the test unless successfully parsed.

Change-Id: I0da9a8f13eb96d950af8c85df17d1899a853a299
diff --git a/test/455-checker-gvn/src/Main.java b/test/455-checker-gvn/src/Main.java
index e94fc46..9824f27 100644
--- a/test/455-checker-gvn/src/Main.java
+++ b/test/455-checker-gvn/src/Main.java
@@ -19,15 +19,15 @@
     System.out.println(foo(3, 4));
   }
 
-  // CHECK-START: int Main.foo(int, int) GVN (before)
-  // CHECK: Add
-  // CHECK: Add
-  // CHECK: Add
+  /// CHECK-START: int Main.foo(int, int) GVN (before)
+  /// CHECK: Add
+  /// CHECK: Add
+  /// CHECK: Add
 
-  // CHECK-START: int Main.foo(int, int) GVN (after)
-  // CHECK: Add
-  // CHECK: Add
-  // CHECK-NOT: Add
+  /// CHECK-START: int Main.foo(int, int) GVN (after)
+  /// CHECK: Add
+  /// CHECK: Add
+  /// CHECK-NOT: Add
 
   public static int foo(int x, int y) {
     int sum1 = x + y;