RFR 8235262: Move c2i_entry_barrier for x86_32 to shared

[Erik Österlund]

Hi Zhengyu,

Since the 32 bit stuff is just a copy paste of the 64 bit stuff, with 
some small tweaks, I think it might be easier to read and maintain if 
you tried to merge the two implementations and just do things different 
where it is different.

Thanks,
/Erik

On 2019-12-04 11:21, Zhengyu Gu wrote:
> When integrating JDK-8230765 [1], I did not integrate 
> c2i_entry_barrier. The implementation is not GC specific, should be 
> moved to shared.
>
> Again, the implementation is very similar to x86_64 version, except it 
> manufactures two temporary registers to act as scratch1 and scratch2 
> registers in x86_64.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8235262
> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8235262/webrev.00/index.html
>
>
> Test:
>   hotspot_gc (fastdebug and release) with x86_64 and x86_32 JVM on Linux
>   submit tests
>
>
> Thanks,
>
> -Zhengyu
>
> [1] https://bugs.openjdk.java.net/browse/JDK-8230765
>