git: openjdk/mobile: 8243325: Cleanup TaskQueueSuper<>::peek

[duke]

Changeset: 5b066096
Author:    Kim Barrett <kbarrett at openjdk.org>
Date:      2020-05-06 00:23:51 +0000
URL:       https://git.openjdk.java.net/mobile/commit/5b066096

8243325: Cleanup TaskQueueSuper<>::peek

Replaced uses of peek with new assert_empty.

Reviewed-by: tschatzl, sjohanss

! src/hotspot/share/gc/shared/taskTerminator.cpp
! src/hotspot/share/gc/shared/taskTerminator.hpp
! src/hotspot/share/gc/shared/taskqueue.hpp