[PATCH] Make use of isAtLeastRelease/Acquire in the ARM/AArch64 backends

[JF Bastien]

Looks good to me beyond the comment on asserts. I'll let others OK the change since I haven't touched that code base.

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Comment at: lib/Target/AArch64/AArch64InstrAtomics.td:32
@@ -31,3 +31,1 @@
   AtomicOrdering Ordering = cast<AtomicSDNode>(N)->getOrdering();
-  assert(Ordering != AcquireRelease && "unexpected load ordering");
-  return Ordering == Acquire || Ordering == SequentiallyConsistent;
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You probably want to keep this assert. Although it is weird that subsequent code doesn't have similar asserts (I'd expect consistency in all-asserts or none).

http://reviews.llvm.org/D4937