Suggest typing.Any when using any as type (#12185)

mypy/typeanal.py

@@ -492,7 +492,10 @@ def analyze_unbound_type_without_type_info(self, t: UnboundType, sym: SymbolTabl
             message = 'Variable "{}" is not valid as a type'
         elif isinstance(sym.node, (SYMBOL_FUNCBASE_TYPES, Decorator)):
             message = 'Function "{}" is not valid as a type'
-            notes.append('Perhaps you need "Callable[...]" or a callback protocol?')
+            if name == 'builtins.any':
+                notes.append('Perhaps you meant "typing.Any" instead of "any"?')
+            else:
+                notes.append('Perhaps you need "Callable[...]" or a callback protocol?')
         elif isinstance(sym.node, MypyFile):
             # TODO: suggest a protocol when supported.
             message = 'Module "{}" is not valid as a type'

test-data/unit/check-functions.test

@@ -2605,3 +2605,8 @@ def foo() -> None:
     pass
 
 reveal_type(foo()) # N: Revealed type is "None"
+
+[case testAnyArgument]
+def a(b: any): pass # E: Function "builtins.any" is not valid as a type \
+                    # N: Perhaps you meant "typing.Any" instead of "any"?
+[builtins fixtures/any.pyi]

test-data/unit/fixtures/any.pyi

@@ -0,0 +1,8 @@
+from typing import TypeVar, Iterable
+
+T = TypeVar('T')
+
+class int: pass
+class str: pass
+
+def any(i: Iterable[T]) -> bool: pass