Convert more tests over to the new atomic instructions.

Convert more tests over to the new atomic instructions.

I did not convert Atomics-32.ll and Atomics-64.ll by hand; the diff is autoupgrade output.

The wmb test is gone because there isn't any way to express wmb with the new atomic instructions; if someone really needs a non-asm way to write a wmb on Alpha, a platform-specific intrisic could be added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140566 91177308-0d34-0410-b5e6-96231b3b80d8