hg: jdk/jdk: 8250825: C2 crashes with assert(field != __null) failed: missing field

[jiefu at tencent.com]

Changeset: bd4d4ab3c2c1
Author:    jiefu
Date:      2020-07-31 17:10 +0800
URL:       https://hg.openjdk.java.net/jdk/jdk/rev/bd4d4ab3c2c1

8250825: C2 crashes with assert(field != __null) failed: missing field
Reviewed-by: kvn, thartmann

! src/hotspot/share/opto/type.cpp
+ test/hotspot/jtreg/compiler/unsafe/TestMisalignedUnsafeAccess.java