Adjust the comment to be about GCC 6.x (for x >= 1).

Fixes #102.

Change-Id: I6fe7439236aa0d0061977627cf5afe398b218815
Reviewed-on: https://code-review.googlesource.com/20490
Reviewed-by: Paul Wankadia <junyer@google.com>
diff --git a/re2/dfa.cc b/re2/dfa.cc
index 2720a5e..bc81fea 100644
--- a/re2/dfa.cc
+++ b/re2/dfa.cc
@@ -126,7 +126,7 @@
                         // into this state, along with kFlagMatch if this
                         // is a matching state.
 
-// Work around the bug affecting flexible array members in GCC 6.1 and 6.2.
+// Work around the bug affecting flexible array members in GCC 6.x (for x >= 1).
 // (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70932)
 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ == 6 && __GNUC_MINOR__ >= 1
     std::atomic<State*> next_[0];   // Outgoing arrows from State,