hg: graal/graal-jvmci-8: Add LoadLoad to the implicit memory barriers on AMD64

[doug.simon at oracle.com]

Changeset: 6758183dd36b
Author:    Benoit Daloze <benoit.daloze at jku.at>
Date:      2016-02-26 13:21 +0100
URL:       http://hg.openjdk.java.net/graal/graal-jvmci-8/rev/6758183dd36b

Add LoadLoad to the implicit memory barriers on AMD64

* See http://gee.cs.oswego.edu/dl/jmm/cookbook.html
  and src/cpu/x86/vm/c1_LIRAssembler_x86.cpp for reference.

! jvmci/jdk.vm.ci.amd64/src/jdk/vm/ci/amd64/AMD64.java