Apply patch 3224663 for Tcl - NULL value fixes and performance improvements for classes with many methods.

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@12563 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/tcl/null_pointer_runme.tcl

@@ -0,0 +1,21 @@
+if [ catch { load ./null_pointer[info sharedlibextension] null_pointer} err_msg ] {
+	puts stderr "Could not load shared object:\n$err_msg"
+}
+
+set a [A]
+if {[func $a] != 0} {
+    puts stderr "null_pointer test 1 failed"
+    exit 1
+}
+
+set null [getnull]
+if {$null != "NULL"} {
+    puts stderr "null_pointer test 2 failed"
+    exit 1
+}
+
+if {[llength [info commands "NULL"]] != 0} {
+    puts stderr "null_pointer test 3 failed"
+    exit 1
+}
+