debug-engine: fix a few type mismatches (#4189)

- use strict prototypes complained by GCC `-Wstrict-prototypes`
- use `int*` instead of `int32*`

Note: on some targets, int32_t is a long.
for example, GCC shipped with the recent ESP-IDF has such a
configuration.

- https://github.com/apache/nuttx/issues/15755#issuecomment-2635652808
- https://github.com/apache/nuttx/pull/16022
- https://docs.espressif.com/projects/esp-idf/en/stable/esp32/migration-guides/release-5.x/5.0/gcc.html#espressif-toolchain-changes

core/iwasm/libraries/debug-engine/debug_engine.h

@@ -133,7 +133,7 @@ bool
 wasm_debug_engine_init(char *ip_addr, int32 process_port);
 
 void
-wasm_debug_engine_destroy();
+wasm_debug_engine_destroy(void);
 
 WASMExecEnv *
 wasm_debug_instance_get_current_env(WASMDebugInstance *instance);