Ensure loop marks vars as possibly assigned

src/Psalm/Internal/Analyzer/Statements/Block/LoopAnalyzer.php

@@ -279,6 +279,8 @@ class LoopAnalyzer
 
                             // if there's a change, invalidate related clauses
                             $pre_loop_context->removeVarFromConflictingClauses($var_id);
+
+                            $loop_scope->loop_parent_context->possibly_assigned_var_ids[$var_id] = true;
                         }
 
                         if (isset($loop_scope->loop_context->vars_in_scope[$var_id])

tests/Loop/ForeachTest.php

@@ -1057,6 +1057,21 @@ class ForeachTest extends \Psalm\Tests\TestCase
                         }
                     }'
             ],
+            'loopCanUpdateOuter' => [
+                '<?php
+                    /**
+                     * @param array<int> $mappings
+                     */
+                    function foo(string $id, array $mappings) : void {
+                        if ($id === "a") {
+                            foreach ($mappings as $value) {
+                                $id = $value;
+                            }
+                        }
+
+                        if (is_int($id)) {}
+                    }'
+            ],
         ];
     }