Filter Windows SDK and Compiler directories

This avoids bugs when other directories (like the Driver SDK) show up in
those folders.

Bug: skia:7395
Change-Id: Iee316a7daf8d71223b999de736d63e1dc7fa31f7
Reviewed-on: https://skia-review.googlesource.com/83542
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
diff --git a/gn/highest_version_dir.py b/gn/highest_version_dir.py
index 650154e..1b82697 100644
--- a/gn/highest_version_dir.py
+++ b/gn/highest_version_dir.py
@@ -6,8 +6,10 @@
 # found in the LICENSE file.
 
 import os
+import re
 import sys
 
-dirpath, = sys.argv[1:]
+dirpath = sys.argv[1]
+regex = re.compile(sys.argv[2])
 
-print sorted(os.listdir(dirpath))[-1]
+print sorted(filter(regex.match, os.listdir(dirpath)))[-1]