Clang update.py: don't guard update of LLVM_WIN_REVISION on sys.platform check

tools/clang/scripts/update.py

Index: tools/clang/scripts/update.py
diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
index 89c5b1f1787884af8c2c7f5f8c6af3002e1ad57d..294e652894a1b854bec920ce9152b17717e5d06c 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -20,8 +20,7 @@ LLVM_WIN_REVISION = 'HEAD'
 
 # ASan on Windows is useful enough to use it even while the clang/win is still
 # in bringup. Use a pinned revision to make it slightly more stable.
-if (sys.platform in ['win32', 'cygwin'] and
-    re.search(r'\b(asan)=1', os.environ.get('GYP_DEFINES', ''))):
+if (re.search(r'\b(asan)=1', os.environ.get('GYP_DEFINES', ''))):
   LLVM_WIN_REVISION = '210586'
 
 # Path constants. (All of these should be absolute paths.)