luaposix: remove eglibc remnants

As a side-effect, this adds the getlogin function back when using glibc.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>

lang/luaposix/patches/100-eglibc-compat.patch

@@ -1,30 +0,0 @@
-diff --git a/ext/posix/unistd.c b/ext/posix/unistd.c
-index 9276640..69c8cef 100644
---- a/ext/posix/unistd.c
-+++ b/ext/posix/unistd.c
-@@ -525,6 +525,7 @@ Pgetgroups(lua_State *L)
- #endif
- 
- 
-+#ifndef NO_GETLOGIN
- /***
- Current logged-in user.
- @treturn[1] string username, if successful
-@@ -537,6 +538,7 @@ Pgetlogin(lua_State *L)
- 	checknargs(L, 0);
- 	return pushstringresult(getlogin());
- }
-+#endif
- 
- 
- /***
-@@ -1044,7 +1046,9 @@ static const luaL_Reg posix_unistd_fns[] =
- 	LPOSIX_FUNC( Pgetegid		),
- 	LPOSIX_FUNC( Pgeteuid		),
- 	LPOSIX_FUNC( Pgetgid		),
-+#ifndef NO_GETLOGIN
- 	LPOSIX_FUNC( Pgetlogin		),
-+#endif
- 	LPOSIX_FUNC( Pgetpgrp		),
- 	LPOSIX_FUNC( Pgetpid		),
- 	LPOSIX_FUNC( Pgetppid		),