Currently we cannot convert a vector load into scalar if there
is dominating barrier or fence. It is considered a clobbering
memory access to prevent memory operations reordering. While
reordering is not possible the actual memory is not being clobbered
by a barrier or fence and we can still use a scalar load for a
uniform pointer.
The solution is not to bail on a first clobbering access but
traverse MemorySSA to the root excluding barriers and fences.
Don't need extra new line