Fix occurrence typing for record/tuple unions

Summary: Fix overlap calculation between record types and tuple types by adding an arity check.

Reviewed By: TD5

Differential Revision: D85806277

fbshipit-source-id: ae17d5c157a1519994da1924542879c37566645a

Author: VLanvin

crates/elp/src/resources/test/eqwalizer_tests/eqwater/deep_tuples.pretty

@@ -30,26 +30,4 @@ error: incompatible_types (See https://fb.me/eqwalizer_errors#incompatible_types
 Expression has type:   'ok'
 Context expected type: none()
 
-error: incompatible_types (See https://fb.me/eqwalizer_errors#incompatible_types)
-   ┌─ eqwater/src/deep_tuples.erl:38:19
-   │
-38 │ test5({ok, V}) -> V.
-   │                   ^
-   │                   │
-   │                   V.
-Expression has type:   'a' | 'ok'
-Context expected type: 'ok'
-   │                   
-
-Because in the expression's type:
-  Here the type is a union type with some valid candidates: 'ok'
-  However the following candidate: 'a'
-  Differs from the expected type:  'ok'
-
------------------------------- Detailed message ------------------------------
-
-  'a' | 'ok' is not compatible with 'ok'
-  because
-  'a' is not compatible with 'ok'
-
-5 ERRORS
+4 ERRORS

crates/elp/src/resources/test/eqwalizer_tests/eqwater/eqwater.pretty

@@ -352,28 +352,6 @@ Because in the expression's type:
   because
   tuple() is not compatible with atom()
 
-error: incompatible_types (See https://fb.me/eqwalizer_errors#incompatible_types)
-    ┌─ eqwater/src/eqwater.erl:681:18
-    │
-681 │     {_N, _N1} -> X#one_field.f1
-    │                  ^
-    │                  │
-    │                  X.
-Expression has type:   #one_field{} | #two_fields1{}
-Context expected type: #one_field{}
-    │                  
-
-Because in the expression's type:
-  Here the type is a union type with some valid candidates: #one_field{}
-  However the following candidate: #two_fields1{}
-  Differs from the expected type:  #one_field{}
-
------------------------------- Detailed message ------------------------------
-
-  #one_field{} | #two_fields1{} is not compatible with #one_field{}
-  because
-  #two_fields1{} is not compatible with #one_field{}
-
 error: incompatible_types (See https://fb.me/eqwalizer_errors#incompatible_types)
     ┌─ eqwater/src/eqwater.erl:839:27
     │
@@ -673,4 +651,4 @@ error: incompatible_types (See https://fb.me/eqwalizer_errors#incompatible_types
 Expression has type:   fun((term(), term()) -> term())
 Context expected type: 'ok'
 
-39 ERRORS
+38 ERRORS