Python: test MaD syntax for keyword argument

use the combined positional/keyword syntax as
that is what we will probably mostly use.

Author: yoff

python/ql/test/experimental/dataflow/model-summaries/NormalDataflowTest.ext.yml

@@ -3,7 +3,7 @@ extensions:
       pack: codeql/python-all
       extensible: summaryModel
     data:
-      - ["foo", "Member[MS_identity]", "Argument[0]", "ReturnValue", "value"]
+      - ["foo", "Member[MS_identity]", "Argument[0,x:]", "ReturnValue", "value"]
       - ["foo", "Member[MS_apply_lambda]", "Argument[1]", "Argument[0].Parameter[0]", "value"]
       - ["foo", "Member[MS_apply_lambda]", "Argument[0].ReturnValue", "ReturnValue", "value"]
       - ["foo", "Member[MS_reversed]", "Argument[0].ListElement", "ReturnValue.ListElement", "value"]

python/ql/test/experimental/dataflow/model-summaries/model_summaries.py

@@ -36,6 +36,10 @@ def SINK_F(x):
 via_identity = MS_identity(SOURCE)
 SINK(via_identity)  # $ flow="SOURCE, l:-1 -> via_identity"
 
+# Simple summary keyword
+via_identity_kw = MS_identity(x = SOURCE)
+SINK(via_identity_kw)  # $ flow="SOURCE, l:-1 -> via_identity_kw"
+
 # Lambda summary
 via_lambda = MS_apply_lambda(lambda x: [x], SOURCE)
 SINK(via_lambda[0])  # $ flow="SOURCE, l:-1 -> via_lambda[0]"