Fix DSE to not nuke dead stores unless they redundant store is the same VT as the killing one.  Fix fixes PR491
Fix DSE to not nuke dead stores unless they redundant store is the same
VT as the killing one.  Fix fixes PR491


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@24034 91177308-0d34-0410-b5e6-96231b3b80d8

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