tainting: Fix --pro-intrafile confusing param with function (semgrep/…

…semgrep-proprietary#1792)

Due to Naming_AST limitations (top-level functions typically do not get
resolved), we ignore the "sid" when matching function names for
inter-proc analysis in `--pro-intrafile`. Problem is that we also
ignored the `id_resolved` in its entirety, and if e.g. this is set to
`LocalVar` or `Param` then that name cannot correspond to a function.
This could lead to a parameter being confused as a function definition
with the same name:

     def foo
       taint
     end

     def bar(foo)
       sink(foo) # this `foo` is the parameter not the function above !
     end

Closes CODE-6923

test plan:
make test # one new test

synced from Pro ca178a77ca44c1fff2105e9d27bd602df1c269b7

changelog.d/code-6923.fixed

@@ -0,0 +1,10 @@
+tainting: Fixed bug in `--pro-intrafile` that caused Semgrep to confuse a parameter
+with a top-level function with no arguments that happened to have the same name:
+
+    def foo
+      taint
+    end
+
+    def bar(foo)
+      sink(foo) # no more FP here
+    end