Fix spelling of Perl 6 (#3672)

Resolves #3671.

samples/Perl 6/01-dash-uppercase-i.t

@@ -0,0 +1,97 @@
+use v6;
+
+use Test;
+
+=begin pod
+
+Test handling of -I.
+
+Multiple C<-I> switches are supposed to
+prepend left-to-right:
+
+  -Ifoo -Ibar
+
+should make C<@*INC> look like:
+
+  foo
+  bar
+  ...
+
+Duplication of directories on the command line is mirrored
+in the C<@*INC> variable, so C<pugs -Ilib -Ilib> will have B<two>
+entries C<lib/> in C<@*INC>.
+
+=end pod
+
+# L<S19/Reference/"Prepend directories to">
+
+my $fragment = '-e "@*INC.perl.say"';
+
+my @tests = (
+    'foo',
+    'foo$bar',
+    'foo bar$baz',
+    'foo$foo',
+);
+
+plan @tests*2;
+
+diag "Running under $*OS";
+
+my ($pugs,$redir) = ($*EXECUTABLE_NAME, ">");
+
+if $*OS eq any <MSWin32 mingw msys cygwin> {
+  $pugs = 'pugs.exe';
+  $redir = '>';
+};
+
+sub nonce () { return (".{$*PID}." ~ (1..1000).pick) }
+
+sub run_pugs ($c) {
+  my $tempfile = "temp-ex-output" ~ nonce;
+  my $command = "$pugs $c $redir $tempfile";
+  diag $command;
+  run $command;
+  my $res = slurp $tempfile;
+  unlink $tempfile;
+  return $res;
+}
+
+for @tests -> $t {
+  my @dirs = split('$',$t);
+  my $command;
+  # This should be smarter about quoting
+  # (currently, this should work for WinNT and Unix shells)
+  $command = join " ", map { qq["-I$_"] }, @dirs;
+  my $got = run_pugs( $command ~ " $fragment" );
+  $got .= chomp;
+
+  if (substr($got,0,1) ~~ "[") {
+    # Convert from arrayref to array
+    $got = substr($got, 1, -1);
+  };
+
+  my @got = EVAL $got;
+  @got = @got[ 0..@dirs-1 ];
+  my @expected = @dirs;
+
+  is @got, @expected, "'" ~ @dirs ~ "' works";
+
+  $command = join " ", map { qq[-I "$_"] }, @dirs;
+  $got = run_pugs( $command ~ " $fragment" );
+  
+  $got .= chomp;
+  if (substr($got,0,1) ~~ "[") {
+    # Convert from arrayref to array
+    $got = substr($got, 1, -1);
+  };
+  
+  @got = EVAL $got;
+  @got = @got[ 0..@dirs-1 ];
+  @expected = @dirs;
+
+  is @got, @expected, "'" ~ @dirs ~ "' works (with a space delimiting -I)";
+}
+
+
+# vim: ft=perl6