RFR: 8270179: Rename Amalloc_4 [v4]

[Coleen Phillimore]

On Mon, 12 Jul 2021 23:56:21 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> This renames Amalloc_4 to AmallocWords.  While I had to fix internal_malloc_4, which is a copy of Amalloc_4 (except with UseMallocOnly handling), I also made the change for
>> JDK-8270217 Fix Arena::Amalloc to check for overflow better
>> Tested with tier1 - all Oracle platforms and tier1-3 on linux-x64.
>
> Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rename internal_malloc_only to internal_amalloc, which is a better name.

Thanks Kim and Thomas.  I filed JDK-8270308 for the alignment issue.  I almost fixed it with this but then I'd want to write a gtest and don't really have 32 bit platforms to conveniently test it on. The comments can be made more clear if someone fixes that bug (assuming the comments refer to alignment).
Thanks for all the reviews and improvements!

-------------

PR: https://git.openjdk.java.net/jdk/pull/4750