[HIPIFY][perl] Support of 'using namespace cub'

bin/hipify-perl

@@ -1676,6 +1676,12 @@ sub transformKernelLaunch {
     }
 }
 
+sub transformCubNamespace {
+    my $k = 0;
+    $k += s/using\s*namespace\s*cub/using namespace hipcub/g;
+    return $k;
+}
+
 sub transformHostFunctions {
     my $k = 0;
     foreach $func (
@@ -2368,6 +2374,7 @@ while (@ARGV) {
         simpleSubstitutions();
         transformExternShared();
         transformKernelLaunch();
+        transformCubNamespace();
         if ($print_stats) {
             while (/(\b(hip|HIP)([A-Z]|_)\w+\b)/g) {
                 $convertedTags{$1}++;