RFR: 8255562: delete UseRDPCForConstantTableBase [v3]

[Volker Simonis]

On Thu, 5 Nov 2020 05:49:11 GMT, Xin Liu <xliu at openjdk.org> wrote:

>> UseRDPCForConstantTableBase was a SPARC-exclusive flag. Sparc has been removed 
>> from hotspot, so remove this flag.
>
> Xin Liu has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:
> 
>  - 8255562: delete UseRDPCForConstantTableBase
>    
>    mark UseRDPCForConstantTableBase is obsoletd in jdk16 and will expire in jdk17.
>  - 8255562: delete UseRDPCForConstantTableBase

Hi Xin,
you also have to remove the option from `c2_globals.hpp`. Also, please add the line 
{ "UseRDPCForConstantTableBase",  JDK_Version::undefined(), JDK_Version::jdk(16), JDK_Version::jdk(17) },
unconditionally (e.g. after the line for the `Debugging` option). You've added it to the `#ifndef COMPILER2` section. I suppose that's the reason why you haven't seen the deprecation warning.

I think if you add the option unconditionally to `special_jvm_flags` you shouldn't need any changes to `Arguments::handle_aliases_and_deprecation`.

You can have a look at [8252889: Obsolete -XX:+InsertMemBarAfterArraycopy](https://bugs.openjdk.java.net/browse/JDK-8252889) for an example.

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Changes requested by simonis (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/949