stage2: elem vals of many pointers need not deref pointers
By the time zirElemVal is reached for a many pointer, a load has already
happened, making sure the operand is already dereferenced.
This makes `mem.sliceTo` now work.
55ccf4c7a8Mitchell Hashimoto committed on 3/8/2022, 7:10:43 PM· committed by Andrew Kelleyparent6ffa445