gh-117174: Rename <string> to <__interactive_string__> for interactive code objects

Using <string> leads to confusion when linecache it's populated with
<string> entries as the inspect module heavily relies on it. An example:

./python -c "import inspect;x=eval('lambda x: x');print(inspect.getsource(x))"

The code above should trigger an exception because we should not be able
to get the source of x (it's dynamically generated) but if we use
<string> as name for interactive code it will return gives the full string.

Signed-off-by: Pablo Galindo <[email protected]>

Author: pablogsal

Misc/NEWS.d/next/Core and Builtins/2024-04-03-11-53-41.gh-issue-117174.FVmuXI.rst

@@ -0,0 +1,3 @@
+Rename ``<string>`` to ``<__interactive_string__>`` for interactive source
+lines to avoid unwanted collisions with other dynamically generated code.
+Patch by Pablo Galindo

Modules/main.c

@@ -249,7 +249,7 @@ pymain_run_command(wchar_t *command)
 
     PyCompilerFlags cf = _PyCompilerFlags_INIT;
     cf.cf_flags |= PyCF_IGNORE_COOKIE;
-    ret = _PyRun_SimpleStringFlagsWithName(PyBytes_AsString(bytes), "<string>", &cf);
+    ret = _PyRun_SimpleStringFlagsWithName(PyBytes_AsString(bytes), "<__interactive_string__>", &cf);
     Py_DECREF(bytes);
     return (ret != 0);