When MachineLICM is hoisting a physical register after regalloc, make sure the register is not killed in the loop.
When MachineLICM is hoisting a physical register after regalloc, make sure the
register is not killed in the loop.

This fixes 188.ammp on ARM where the post-ra scheduler would grab a register
that looked available but wasn't.

A testcase would be huge and fragile, sorry.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@101930 91177308-0d34-0410-b5e6-96231b3b80d8

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