Add IO::Spec::QNX to make Unix more efficient

QNX and Neutrino(nto) use //path special syntax, but there's no need
to penalize every other unix with extra operations in canonpath.
Plus it was never tested on qnx so it didn't even work... now fixed
Seriously, what bozo implemented this in the first place?

src/core/IO/Spec.pm

@@ -8,6 +8,9 @@ my class IO::Spec {
         'Win32'   => 'Win32',
         'cygwin'  => 'Cygwin',
         'Cygwin'  => 'Cygwin',
+        'qnx'     => 'QNX',
+        'QNX'     => 'QNX',
+        'nto'     => 'QNX',
         # <MacOS Mac>  »=>» 'Mac',
         # 'VMS'     => 'VMS'
 );

src/core/IO/Spec/QNX.pm

@@ -0,0 +1,17 @@
+my class IO::Spec::QNX is IO::Spec::Unix {
+
+    method canonpath ($path is copy, :$parent) { 
+        # Handle POSIX-style node names beginning with double slash (qnx, nto)
+        # (POSIX says: "a pathname that begins with two successive slashes
+        # may be interpreted in an implementation-defined manner, although
+        # more than two leading slashes shall be treated as a single slash.")
+        my $node = '';
+        if $path ~~ s {^ ( '//' <-[ / ]>+ ) '/'? $} = ''
+        or $path ~~ s {^ ( '//' <-[ / ]>+ ) '/' }   = '/' 
+            { $node = ~ $0; }
+
+        $path = IO::Spec::Unix.canonpath($path, :$parent);
+
+        $node ~ $path;
+    }
+}

src/core/IO/Spec/Unix.pm

@@ -2,19 +2,8 @@ my class IO::Spec { ... }
 
 my class IO::Spec::Unix {
 
-    method canonpath( $path is copy ) {
-        $path;
-        return unless $path.defined;
-
-        # Handle POSIX-style node names beginning with double slash (qnx, nto)
-        # (POSIX says: "a pathname that begins with two successive slashes
-        # may be interpreted in an implementation-defined manner, although
-        # more than two leading slashes shall be treated as a single slash.")
-        my $node = '';
-        if ( so $*OS eq 'qnx'|'nto' )   #double slashes special on these OSes
-           && (   $path ~~ s {^ ( '//' <-[ / ]>+ ) '/'? $} = ''
-               || $path ~~ s {^ ( '//' <-[ / ]>+ ) '/' }   = '/' )
-               { $node = ~ $0; }
+    method canonpath( $path is copy --> Str ) {
+        return '' if $path eq '';
 
         $path ~~ s:g { '//' '/'* }         = '/';     # xx////xx  -> xx/xx  
         $path ~~ s:g { '/.'+ ['/' | $] }   = '/';     # xx/././xx -> xx/xx  
@@ -23,11 +12,10 @@ my class IO::Spec::Unix {
         unless $path eq "/" {
             $path ~~ s { '/' $ }       = '';      # xx/       -> xx    :)
         }
-
-        return "$node$path";
+        $path;
     }
 
-    method curdir {    '.'  }
+    method curdir {  '.' }
     method updir  { '..' }
     method rootdir { '/' }
     method devnull { '/dev/null' }

tools/build/Makefile-Parrot.in

@@ -212,6 +212,7 @@ CORE_SOURCES = \
   src/core/IO/Spec/Unix.pm \
   src/core/IO/Spec/Win32.pm \
   src/core/IO/Spec/Cygwin.pm \
+  src/core/IO/Spec/QNX.pm \
   src/core/IO/Spec.pm \
   src/core/IO.pm \
   src/core/IO/ArgFiles.pm \