[6.0] 568e6ec29 Add a comment for future reference

[Dridi Boukelmoune]

commit 568e6ec2946cb84d6209e483ae87994f5c20c27b
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Fri Jun 8 10:05:03 2018 +0100

    Add a comment for future reference

diff --git a/bin/varnishtest/tests/c00057.vtc b/bin/varnishtest/tests/c00057.vtc
index ec90cc864..2b2f38891 100644
--- a/bin/varnishtest/tests/c00057.vtc
+++ b/bin/varnishtest/tests/c00057.vtc
@@ -1,5 +1,7 @@
 varnishtest	"test sigsegv handler"
 
+# Under ASAN, the stack layout is different and STACK OVERFLOW is
+# never printed.
 feature cmd "test -z $(env | grep ASAN_OPTIONS)"
 
 server s1 {