pat_advanced.t: Simplify a test

I made this test to look as much as possible as the original report.
Hugo van der Sanden pointed out that the encodes and decode together
were essentially a no-op; so this commit removes them.

diff --git a/t/re/pat_advanced.t b/t/re/pat_advanced.t
index c469d5c..8c69095 100644 (file)
--- a/t/re/pat_advanced.t
+++ b/t/re/pat_advanced.t
@@ -2565,12 +2565,9 @@ EOF
     {   # GH $17278 assertion fails
         fresh_perl_is('use locale;
                        my $A_grave = "\N{LATIN CAPITAL LETTER A WITH GRAVE}";
-                       utf8::encode($A_grave);
                        my $a_grave = "\N{LATIN SMALL LETTER A WITH GRAVE}";
-                       utf8::encode($a_grave);
 
                        my $z="q!$a_grave! =~ m!(?^i)[$A_grave]!";
-                       utf8::decode($z);
                        print eval $z, "\n";',
                        1,
                        {}, "GH #17278");