hg: shenandoah/jdk: Revert "macro assembler's enqueue barrier register allocation"

[ashipile at redhat.com]

Changeset: a6db1faa4776
Author:    shade
Date:      2018-06-19 14:34 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/a6db1faa4776

Revert "macro assembler's enqueue barrier register allocation"

! src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp