Revert "[AssumptionCache] Avoid dangling llvm.assume calls in the cache"

This reverts commit b7d870eae7fdadcf10d0f177faa7409c2e37d776 and the
subsequent fix "[Polly] Fix build after AssumptionCache change (D96168)"
(commit e6810cab09fcbc87b6e5e4d226de0810e2f2ea38).

It caused indeterminism in the output, such that e.g. the
polly-x86_64-linux buildbot failed accasionally.

GitOrigin-RevId: 606aa622b23855784c5db5b48b1c4800467fd851
1 file changed