RFR (XS) 8198311: Avoid uses of global malloc and free

[Kim Barrett]

> On Feb 16, 2018, at 6:09 PM, coleen.phillimore at oracle.com wrote:
> 
> Summary: fix two places that improperly use global malloc and free
> 
> Tested by tier1 in mach5 which includes aot tests.
> 
> open webrev at http://cr.openjdk.java.net/~coleenp/8198311.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8198311
> 
> Thanks,
> Coleen

Looks good.