Ignore s/…/…/ and possibly some other things

To prevent misdetection like here:
http://colabti.org/irclogger/irclogger_log/perl6?date=2018-02-06#l249

Author: AlexDaniel

bin/Evalable.p6

@@ -72,6 +72,7 @@ method process($msg, $code is copy, :$good-only?) {
         return if $result<exit-code> ≠ 0;
         return if !$output;
         return if $output ~~ /^‘WARNINGS for ’\N*\n‘Useless use’/;
+        return if $output ~~ /^‘Potential difficulties:’/;
         return if $output ~~ /^‘Use of uninitialized value of type Any in string context.’/;
     }
     my $extra  = ‘’;

t/evalable.t

@@ -222,6 +222,9 @@ $t.test(‘empty output is ignored’,
 $t.test(‘timeouts are ignored’,
         ‘sleep ∞’);
 
+$t.test(‘s/…/…/ is ignored’,
+        ‘s/each block/each comp unit/;’);
+
 $t.test(‘segfaults are not ignored’,
         ‘use NativeCall; sub strdup(int64) is native(Str) {*}; strdup(0)’,
         /^ <me($t)>‘, rakudo-moar ’<sha>‘: OUTPUT: «(signal SIGSEGV) »’ $/);