pp_aassign: scan on DEBUGGING builds

At compile-time we often decide that a list assign op is safe from
possible commonality (($a,$b) = ($b,$a)), and so skip the run-time
mark-and-sweep commonality finder.

This commit makes it always mark-and-sweep at runtime, and to panic if
if finds commonality when at compile-time we had determined that there
couldn't possibly be any.

This commit fails the t/perf/benchmark.t test as it contains something
which triggers the panic. This will be fixed in the next commit.

1 files changed, 4 insertions, 1 deletions

diff --git a/t/op/aassign.t b/t/op/aassign.t
index e73e172ed2..58650b72f3 100644
--- a/t/op/aassign.t
+++ b/t/op/aassign.t
@@ -269,7 +269,10 @@ sub sh {
 # b) it's such an important usage that for performance reasons we
 #    mark it as safe even though it isn't really. Hence it's a TODO.
 
-{
+SKIP: {
+    use Config;
+    # debugging builds will detect this failure and panic
+    skip "DEBUGGING build" if $::Config{config_args} =~ /DEBUGGING/;
     local $::TODO = 'cheat and optimise my (....) = @_';
     local @_ = 1..3;
     &f17;