swr: [rasterizer scripts] add ENABLE_ASSERT_DIALOGS knob for windows

Signed-off-by: Tim Rowley <timothy.o.rowley@intel.com>

src/gallium/drivers/swr/rasterizer/scripts/knob_defs.py

@@ -22,6 +22,14 @@
 # Python source
 KNOBS = [
 
+    ['ENABLE_ASSERT_DIALOGS', {
+        'type'      : 'bool',
+        'default'   : 'true',
+        'desc'      : ['Use dialogs when asserts fire.',
+                       'Asserts are only enabled in debug builds'],
+        'category'  : 'debug',
+    }],
+
     ['SINGLE_THREADED', {
         'type'      : 'bool',
         'default'   : 'false',