RFR: 8003310: Enable -Wunused when compiling with GCC

[Vladimir Kozlov]

In opto/subnode.cpp leave the beginning of commented code to explain why 
we don't do such optimizations.

Thanks,
Vladimir

On 11/12/12 19:59, Mikael Vidstedt wrote:
>
> All,
>
> Please review the below change. The change adds the -Wunused flag when
> compiling with GCC and removes a number of unused functions/dead code.
>
> In the process I found one function (same_page) which was duplicated in
> four different places. I merged it to a single function, renamed it to
> clamp_address_in_page, added some comments and refactored it to be
> slightly easier to understand. I also added unit tests for it. Feedback
> appreciated (especially on the name).
>
> http://cr.openjdk.java.net/~mikael/8003310/webrev.00/
>
> Passes JPRT and the built-in unit tests (-XX:+ExecuteInternalVMTests).
>
> Thanks,
> Mikael
>