remove inside_constructor flag on Typing_env.env

Summary:
# What
We currently hold two flags on the typing environment

1) `env.inside_constructor` - set when we typecheck a constructor, then we call
`method_def` in `typing_class.ml`
2) `env.genv.fun_is_ctor` - set when we call `method_def` in `typing_class.ml`
by inspecting the name of the method and doing some string comparison.

Given that these two fields do the same thing, I'm removing the one from `env`.
# Why
For const props, I'd like to enforce checking writes to a const prop during
function calls, but not when typechecking method defs. I may need to carry
another flag on the typing environment `inside_method_def` or something
similar. Before adding a field, I figured I'd clean up here and pay off my
cost.

Reviewed By: mheiber

Differential Revision: D83250939

fbshipit-source-id: 72a825dd8da6484909ff707c361d1d2d3de46bce

Author: Nikhil Thomas

hphp/hack/src/typing/tast_env.ml

@@ -118,9 +118,13 @@ let get_underlying_function_type env ty =
   opt_ft
 
 let set_inside_constructor env =
-  { env with Typing_env_types.inside_constructor = true }
+  {
+    env with
+    Typing_env_types.genv =
+      { env.Typing_env_types.genv with fun_is_ctor = true };
+  }
 
-let get_inside_constructor env = env.Typing_env_types.inside_constructor
+let get_inside_constructor env = env.Typing_env_types.genv.fun_is_ctor
 
 let fully_expand = Typing_expand.fully_expand
 

hphp/hack/src/typing/typing_class.ml

@@ -1271,7 +1271,6 @@ let class_const_def ~in_enum_class c cls env cc =
       ty ) )
 
 let class_constr_def ~is_disposable env cls constructor =
-  let env = { env with inside_constructor = true } in
   Option.bind constructor ~f:(method_def ~is_disposable env cls)
 
 (** Type-check a property declaration, with optional initializer *)

hphp/hack/src/typing/typing_env_types.ml

@@ -38,7 +38,6 @@ type env = {
   in_lambda: bool;
   in_expr_tree: expr_tree_env option;
   in_macro_splice: Typing_local_types.t option;
-  inside_constructor: bool;
   checked: Tast.check_status;
   tracing_info: Decl_counters.tracing_info option;
   tpenv: Type_parameter_env.t;
@@ -93,7 +92,6 @@ let empty ?origin ?(mode = FileInfo.Mstrict) ctx file ~droot =
     in_lambda = false;
     in_expr_tree = None;
     in_macro_splice = None;
-    inside_constructor = false;
     checked = Tast.COnce;
     decl_env = { Decl_env.mode; droot; droot_member = None; ctx };
     tracing_info =

hphp/hack/src/typing/typing_env_types.mli

@@ -51,7 +51,6 @@ type env = {
            contains nested expression trees with free variables. local_env contains
            the bindings for those free variables
       *)
-  inside_constructor: bool;
   checked: Tast.check_status;
       (** Set to true when checking if a <<__SoundDynamicallyCallable>> method body
           is well-typed under dyn..dyn->dyn assumptions, that is if it can be safely called

hphp/hack/src/typing/typing_log.ml

@@ -611,7 +611,6 @@ let env_as_value env =
     in_lambda;
     in_expr_tree;
     in_macro_splice;
-    inside_constructor;
     checked;
     tpenv;
     log_levels = _;
@@ -625,6 +624,7 @@ let env_as_value env =
   } =
     env
   in
+  let inside_constructor = env.genv.fun_is_ctor in
   make_map
     [
       ("fresh_typarams", Set fresh_typarams);