[LVI] Don't traverse uses when calculating range at use

This effectively reverts 5c38c6a and 4f772b0.

A recently introduced LazyValueInfo::getConstantRangeAtUse returns incorrect
ranges for values in certain cases. One such example is described in PR60629.
The issue has something to do with traversing PHI uses of a value transitively.
As nikic pointed out, we're effectively reasoning about values from different
loop iterations.

In the faulting test case, CVP made a miscompilation because the calculated
range for a shift argument was incorrect. It returned empty-set, however it is
clearly not a dead code. CVP then erased the shift instruction because
of empty range.

0 files changed, 0 insertions, 0 deletions