Python: Fix problems with missing TAttributeContent

Author: RasmusWL

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPublic.qll

@@ -614,7 +614,7 @@ newtype TContent =
     // instead we use a qltest to alert if we write a new summary in QL that uses an
     // attribute -- see
     // python/ql/test/experimental/dataflow/summaries-checks/missing-attribute-content.ql
-    none() // to be filled out in next commit
+    attr in ["re", "string", "pattern"]
     or
     //
     // 2) summaries in data-extension files

python/ql/test/experimental/dataflow/summaries-checks/invalid-spec.expected

@@ -1,14 +1,2 @@
-| compiled re.Match | Argument[self].Attribute[pattern] | Attribute[pattern] |
-| compiled re.Match | ReturnValue.Attribute[re].Attribute[pattern] | Attribute[pattern] |
-| compiled re.Match | ReturnValue.Attribute[re].Attribute[pattern] | Attribute[re] |
-| compiled re.Match | ReturnValue.Attribute[string] | Attribute[string] |
 | compiled re.subn | ReturnValue.TupleElement[0] | TupleElement[0] |
-| re.Match | ReturnValue.Attribute[re].Attribute[pattern] | Attribute[pattern] |
-| re.Match | ReturnValue.Attribute[re].Attribute[pattern] | Attribute[re] |
-| re.Match | ReturnValue.Attribute[string] | Attribute[string] |
-| re.Match.expand | Argument[self].Attribute[string] | Attribute[string] |
-| re.Match.group | Argument[self].Attribute[string] | Attribute[string] |
-| re.Match.groupdict | Argument[self].Attribute[string] | Attribute[string] |
-| re.Match.groups | Argument[self].Attribute[string] | Attribute[string] |
-| re.Pattern | ReturnValue.Attribute[pattern] | Attribute[pattern] |
 | re.subn | ReturnValue.TupleElement[0] | TupleElement[0] |

python/ql/test/experimental/dataflow/summaries-checks/missing-attribute-content.expected

@@ -1,3 +0,0 @@
-| The attribute "pattern" is not a valid TAttributeContent, please add it to the hardcoded list of TAttributeContent in the dataflow library. |
-| The attribute "re" is not a valid TAttributeContent, please add it to the hardcoded list of TAttributeContent in the dataflow library. |
-| The attribute "string" is not a valid TAttributeContent, please add it to the hardcoded list of TAttributeContent in the dataflow library. |