RFR (S) 8228484: Remove NoAllocVerifier because nothing uses it

[Kim Barrett]

> On Jul 22, 2019, at 11:37 AM, coleen.phillimore at oracle.com wrote:
> 
> Tested with mach5 tier1-3.
> 
> open webrev at http://cr.openjdk.java.net/~coleenp/2019/8228484.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8228484
> 
> Thanks,
> Coleen

Looks good.

One comment fix, for which I don’t need a new webrev:

src/hotspot/share/runtime/thread.hpp
 379   // The class NoSafepointVerifier is used to set these counters.

s/these counters/this counter/ -- there's only one counter now.