Currently the liveness analysis always marks operands yielded in regions
that aren't classified as `RegionBranchOpInterface` or
`CallableOpInterface` as non-live. Examples for these ops include
linalg.generic (with `linalg.yield` as terminator) or gpu ops (with
`gpu.yield` as terminator).
This in turn makes the `remove-dead-values` pass always incorrectly
remove the bodies of these ops, leading to invalid IR. Because these ops
define their own semantics, I have conservatively marked all operands of
these yield ops to be live.
7385772fdb