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/gdbserver.h

@@ -51,7 +51,7 @@ typedef struct WASMGDBServer {
 } WASMGDBServer;
 
 WASMGDBServer *
-wasm_create_gdbserver(const char *host, int32 *port);
+wasm_create_gdbserver(const char *host, int *port);
 
 bool
 wasm_gdbserver_listen(WASMGDBServer *server);