Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Export quad symbols. They were previously commented out. These symbols
really shouldn't be exported since they should be pulled from libgcc, but
the build of some applications is broken and they expect to see them in
libc. glibc exports these symbols, although Solaris doesn't appear to,
so export them for compatibility's sake.

After discussion with: kan

Use C comments since we now preprocess these files with CPP.

Add symbol maps and initial symbol version definitions to libc.

Reviewed by: davidxu