Drop EMULATE_FUNCTION_POINTER_CASTS (it broke the wasm32 TCG ffi_call_js
path with BigInt errors) and fix the underlying function-pointer signature
mismatches instead: object_class_cmp GCompareFunc, esp_sha hash-callback
wrappers, and an xts_aes NULL guard in the ESP32-C3 cache. Backport the
upstream Emscripten anonymous-RAM allocator fix. Firmware now boots and
initializes the X3 panel; a post-init boot stall remains.
evan