Python: Re-introduce syntactic handling of str/bytes/unicode (again)

This reverts commit 870389a.

Author: RasmusWL

python/ql/src/semmle/python/dataflow/new/internal/TaintTrackingPrivate.qll

@@ -77,7 +77,11 @@ predicate subscriptStep(DataFlow::CfgNode nodeFrom, DataFlow::CfgNode nodeTo) {
 predicate stringManipulation(DataFlow::CfgNode nodeFrom, DataFlow::CfgNode nodeTo) {
   // transforming something tainted into a string will make the string tainted
   exists(DataFlow::CallCfgNode call | call = nodeTo |
-    call = API::builtin(["str", "bytes", "unicode"]).getACall() and
+    (
+      call = API::builtin(["str", "bytes", "unicode"]).getACall()
+      or
+      call.getFunction().asCfgNode().(NameNode).getId() in ["str", "bytes", "unicode"]
+    ) and
     nodeFrom in [call.getArg(0), call.getArgByName("object")]
   )
   or

python/ql/test/experimental/dataflow/tainttracking/defaultAdditionalTaintStep/InlineTaintTest.expected

@@ -1,5 +1,3 @@
 argumentToEnsureNotTaintedNotMarkedAsSpurious
 untaintedArgumentToEnsureTaintedNotMarkedAsMissing
-| test_string.py:35:9:35:19 | test_string.py:35 | ERROR, you should add `# $ MISSING: tainted` annotation | unicode(..) |
 failures
-| test_string.py:35:22:35:32 | Comment # $ tainted | Missing result:tainted= |