[8u] G1: guarantee(!obj->is_forwarded()) failed: Object must not be forwarde

[wattsun(孙宇)]

Dear All,

     may I hava this small bug fix to review?

     Bug: https://bugs.openjdk.java.net/browse/JDK-8257239

     Webrev: http://cr.openjdk.java.net/~jiefu/watt/8257239/webrev.00/



Jdk8u and jdk9 use oop header to mark live oop, so we should not check obj mark word during marking verification in a full GC





Btw: Jdk10 and later version use parallel fullgc  which use __heap->concurrent_mark()->nextMarkBitMap() to mark a oop live of

 not ,so jdk10 and later version don’t have this bug.



Thanks!

watt