Hi, fans.

I'm trying to port LibreSSL on native Plan 9.
Some functions are works now:

    1. git clone https://github.com/lufia/portable && cd portable
    2. rc ./update.rc
    3. ape/patch -p0 <plan9/crypto.patch
    4. ape/patch -p0 <plan9/ssl.patch
    5. ape/patch -p0 <plan9/apps.patch
    6. for(i in crypto ssl apps/openssl) @{ cd $i; mk }

I have difficulty in porting header files.
Some headers of LibreSSL has #include_next GCC extended directive, but Plan
9's cpp can't process #include_next directive.
When cpp processes a header containing #include_next, it exits with
"Unknown preprocessor control #include_next" error even if ignoring by #if
and #endif.

    % cat <<! | cpp
    #if 0
    #include_next <u.h>
    #endif
    !
    #line 1 "/usr/lufia/<stdin>"
    cpp: <stdin>:2 Unknown preprocessor control include_next

I had no choice but to rewrite #include_next like:

compat.h:
    #ifdef Plan9
    #define SYS_PATH(x) /sys/include/ape/x
    #else
    #define SYS_PATH(x) sys_##x
    #endif
    #define SYSINCLUDE(x) <SYS_PATH(x)>

string.h:
    #include SYSINCLUDE(string.h)

sys_string.h:
    #include_next <string.h>

This works but I think this way is not good because developer should manage
two files.
Is there any good way?