Revert PR python#3205 and python#3235

Author: pkch

mypy/fixup.py

@@ -15,8 +15,6 @@
 )
 from mypy.visitor import NodeVisitor
 
-from mypy.semanal import rev_module_rename_map
-
 
 def fixup_module_pass_one(tree: MypyFile, modules: Dict[str, MypyFile],
                           quick_and_dirty: bool) -> None:
@@ -243,9 +241,6 @@ def lookup_qualified(modules: Dict[str, MypyFile], name: str,
 
 def lookup_qualified_stnode(modules: Dict[str, MypyFile], name: str,
                             quick_and_dirty: bool) -> Optional[SymbolTableNode]:
-    if '_importlib_modulespec' in modules:
-        # we are using python 3, so renaming is necessary
-        name = rev_module_rename_map.get(name, name)
     head = name
     rest = []
     while True:

mypy/semanal.py

@@ -117,20 +117,13 @@
     'typing.typevar': 'typing.TypeVar',
 }
 
-# Used for python 3 only
 # Rename objects placed in _importlib_modulespec due to circular imports
-# Safe in python 2 because no one will ask for these keys
 module_rename_map = {
     '_importlib_modulespec.ModuleType': 'types.ModuleType',
     '_importlib_modulespec.ModuleSpec': 'importlib.machinery.ModuleSpec',
     '_importlib_modulespec.Loader': 'importlib.abc.Loader'
 }
 
-# Must not be used in python 2 (it will replace correct names with incorrect)
-# The check for version is currently made at the point of use
-# TODO: consider moving these maps from global scope to somewhere where python version is known
-rev_module_rename_map = {v: k for (k, v) in module_rename_map.items()}
-
 # Hard coded type promotions (shared between all Python versions).
 # These add extra ad-hoc edges to the subtyping relation. For example,
 # int is considered a subtype of float, even though there is no