Make writeStackCookie() use HEAPU32 (#17648)

Author: benjitrosch

src/runtime_stack_check.js

@@ -17,8 +17,8 @@ function writeStackCookie() {
   // The stack grow downwards towards _emscripten_stack_get_end.
   // We write cookies to the final two words in the stack and detect if they are
   // ever overwritten.
-  {{{ makeSetValue('max', 0, '0x2135467', 'i32' ) }}};
-  {{{ makeSetValue('max', 4, '0x89BACDFE', 'i32' ) }}};
+  {{{ makeSetValue('max', 0, '0x2135467', 'u32' ) }}};
+  {{{ makeSetValue('max', 4, '0x89BACDFE', 'u32' ) }}};
 #if !USE_ASAN && !SAFE_HEAP // ASan and SAFE_HEAP check address 0 themselves
   // Also test the global address 0 for integrity.
   HEAPU32[0] = 0x63736d65; /* 'emsc' */