RFR: 8232084: HotSpot build failed with GCC 9.2.1

[Kim Barrett]

> On Oct 11, 2019, at 11:22 PM, Yasumasa Suenaga <suenaga at oss.nttdata.com> wrote:
> 
> Hi,
> 
> I updated Plan B-1 (#pragma) due to the comment from Chris [1].
> 
> 
>  A. Use memcpy()
>       http://cr.openjdk.java.net/~ysuenaga/JDK-8232084/webrev.02/
> 
>  B-1. Use #pragma
>       http://cr.openjdk.java.net/~ysuenaga/JDK-8232084/webrev.B1-pragma.03/
> 
> 
> I dropped Plan C (disable stringop-truncation in globally) from the solutions
> because Kim pointed this warning found out some actual bugs [2].

Option B1 looks okay to me.

I don't think the second line of the comment:
 156       // So we avoid it via PRAGMA_STRINGOP_TRUNCATION_IGNORED macro.
adds any information and just adds to clutter, given that the pragma
is now right there.  From my POV, remove or don't, as you prefer.