error: unknown type name 'in_addr_t'

When compiling [Valkey](https://github.com/zyuiop/hermit-valkey/) using the latest version of hermit-gcc, the following problem occurs:

```
3.299 In file included from /opt/hermit/x86_64-hermit/include/netinet/in.h:4,
3.299 from sockcompat.h:40,
3.299 from net.c:47:
3.299 /opt/hermit/x86_64-hermit/include/arpa/inet.h:21:1: error: unknown type name 'in_addr_t'; did you mean 'caddr_t'?
3.299 21 | in_addr_t inet_addr(const char *cp);
3.299 | ^~~~~~~~~
3.299 | caddr_t
3.300 /opt/hermit/x86_64-hermit/include/netinet/in.h:14:5: error: unknown type name 'in_addr_t'; did you mean 'caddr_t'?
3.300 14 | in_addr_t s_addr;
3.300 | ^~~~~~~~~
3.300 | caddr_t
3.300 /opt/hermit/x86_64-hermit/include/netinet/in.h:24:5: error: unknown type name 'in_port_t'; did you mean 'intptr_t'?
3.300 24 | in_port_t sin_port;
3.300 | ^~~~~~~~~
3.300 | intptr_t
3.301 /opt/hermit/x86_64-hermit/include/netinet/in.h:32:5: error: unknown type name 'in_port_t'; did you mean 'intptr_t'?
3.301 32 | in_port_t sin6_port;
3.301 | ^~~~~~~~~
3.301 | intptr_t
```

Here is the dockerfile used

```dockerfile
FROM ghcr.io/hermit-os/hermit-gcc:x86_64 AS builder

ENV CC="x86_64-hermit-gcc"
ENV CFLAGS="-DAF_UNIX=99 -DAF_LOCAL=99 -DTIOCGWINSZ=0x5413 -fPIE"
ENV LDFLAGS="-L/hermit -Wl,--as-needed -Wl,--no-undefined -pie -Wl,--whole-archive -Wl,--start-group /hermit/libhermit.a -Wl,--end-group -Wl,--no-whole-archive -pthread"
ENV DEB_HOST_GNU_TYPE="x86_64-hermit"
ENV JEMALLOC_CONFIGURE_OPTS="--disable-syscall"

ARG LIBHERMIT=libhermit.a

WORKDIR /valkey
COPY valkey /valkey
ADD $LIBHERMIT /hermit/libhermit.a

RUN make distclean
RUN make valkey-server MALLOC=libc
```

Reproduce the build with the provided Dockerfile and hermit-gcc command, then inspect /opt/hermit/x86_64-hermit/include/arpa/inet.h, netinet/in.h, and the declarations included by sockcompat.h. Trace where in_addr_t and in_port_t should be defined and compare that with the include order used by net.c. Done means the Valkey build no longer reports these unknown-type errors.

Written by the indexing model from the issue text.