Also unset possibly-in-scope vars

src/Psalm/Checker/TypeChecker.php

@@ -610,7 +610,7 @@ class TypeChecker
                             new FailedTypeResolution('Cannot resolve types for ' . $key, $code_location),
                             $suppressed_issues
                         )) {
-                            return false;
+                            // fall through
                         }
                     }
                 }

src/Psalm/Context.php

@@ -195,6 +195,7 @@ class Context
     public function remove($remove_var_id)
     {
         unset($this->referenced_vars[$remove_var_id]);
+        unset($this->vars_possibly_in_scope[$remove_var_id]);
 
         if (isset($this->vars_in_scope[$remove_var_id])) {
             $type = $this->vars_in_scope[$remove_var_id];