Fix implicit proto for objects with [[call]] properties

Summary:
When an object has a callable property, it is actually a function. As a
function, it's prototype is the function prototype with properties `bind`,
`call`, `apply`, etc.

The code to detect this only considered the original callable property syntax,
but should also consider the newer [[call]] syntax.

Reviewed By: gabelevi

Differential Revision: D14652059

fbshipit-source-id: b83185a8b8bd633d78394bfcbc56a1d5a35d460c

src/typing/type_annotation.ml

@@ -934,7 +934,11 @@ let rec convert cx tparams_map = Ast.Type.(function
 | loc, Object { Object.exact; properties; inexact } ->
   let reason_desc = RObjectType in
   let callable = List.exists (function
-    | Object.CallProperty (_, { Object.CallProperty.static; _ }) -> not static
+    | Object.CallProperty (_, { Object.CallProperty.static; _ })
+    | Object.InternalSlot (_, { Object.InternalSlot.
+        id = (_, { Ast.Identifier.name = "call"; _ });
+        static; _ })
+      -> not static
     | _ -> false
   ) properties in
   let mk_object ~exact (call_props, dict, props_map, proto) =

tests/call_properties/call_properties.exp

@@ -291,8 +291,10 @@ References:
 
 Error --------------------------------------------------------------------------------------------- internal_slot.js:5:2
 
-Cannot cast object literal to `O` because a call signature declaring the expected parameter / return type is missing in
-object literal [1] but exists in `O` [2].
+Cannot cast object literal to `O` because:
+ - object literal [1] is incompatible with function prototype [2].
+ - a call signature declaring the expected parameter / return type is missing in object literal [1] but exists in
+   `O` [2].
 
    internal_slot.js:5:2
    5| ({}: O); // err: no callable property
@@ -434,7 +436,7 @@ References:
 
 
 
-Found 27 errors
+Found 28 errors
 
 Only showing the most relevant union/intersection branches.
 To see all branches, re-run Flow with --show-all-branches