jdk7-b64 has new dependency on glibc-2.4

[Alan Bateman]

Martin Buchholz wrote:
> I approve this change.
>   
Thanks!
> ---
> build time => run time
>
>  188     /* system calls that might not be available at build time */
>   
OK, it's both so let's make it "build or runtime".

> ---
>
> I am ever so slightly tempted to rearchitect a little,
> to have HAS_AT_SYSCALLS be less all-or-nothing,
> and to try to move some of this logic to java code.
>   
The *at calls are a logical group and I can't think of any operating 
system or version where some, but not all, are available. The fdopendir 
is libc so this could be separated. At this time we don't have a current 
usage where we would use fdopendir without the *at calls so that it why 
they are grouped under the same capability.

> ---
>
> I might consider removing the #ifdef
> and unconditionally checking for openat64,
> with fallback to openat.
>
>  190 #if defined(__solaris__) && defined(_LP64)
>  191     /* Solaris 64-bit does not have openat64/fstatat64 */
>  192     my_openat64_func = (openat64_func*)dlsym(RTLD_DEFAULT, "openat");
>  193     my_fstatat64_func = (fstatat64_func*)dlsym(RTLD_DEFAULT, "fstatat");
>  194 #else
>  195     my_openat64_func = (openat64_func*) dlsym(RTLD_DEFAULT, "openat64");
>  196     my_fstatat64_func = (fstatat64_func*) dlsym(RTLD_DEFAULT, "fstatat64");
>  197 #endif
>   
We could but it would mean we'd have to use the O_LARGFILE flag 
explicitly. Not sure it's worth it, just a nuisance that Solaris 64-bit 
doesn't have open64.

-Alan.