RFR: Add a limition to allocate object heap in aarch64 with tsan enabled.

[Man Cao]

On Wed, 22 Apr 2020 02:25:03 GMT, Jie He <github.com+10233373+jhe33 at openjdk.org> wrote:

>> Putting the code related to reasonable_max in os_posix.cpp sounds good.
>> It's better to guard it with TSAN_RUNTIME_ONLY(). We would like to keep "-XX:-ThreadSanitizer" the same as the default
>> JVM configuration.
>
> no, I have to use TSAN_ONLY, otherwise, building java images will fail, where jvm has been used without
> +ThreadSanitizer. In addition, some scripts like jtreg also use "java --version" or other commands without
> +ThreadSanitizer to do some jobs.  I just see other functions has similar style, which define and use the Macros or
> const variables locally, due to merely one use place.

Thanks for explaining. Let's keep using TSAN_ONLY.

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PR: https://git.openjdk.java.net/tsan/pull/6