RFR(s): 8214181: safepoint header cleanup

[Kim Barrett]

> On Nov 22, 2018, at 5:29 AM, Robbin Ehn <robbin.ehn at oracle.com> wrote:
> 
> Here is inc:
> http://cr.openjdk.java.net/~rehn/8214181/v2/inc/webrev/index.html
> Full:
> http://cr.openjdk.java.net/~rehn/8214181/v2/webrev/
> 
> Build locally without precompiled and tier 1.

Looks good.