We were missing the PoisonOnly argument (so Depth + 1 was being used instead and the default Depth = 0 argument then being silently used) Fixes #94145 and serves as the test case for 9e22c7a0ea87228dffcdfd7ab62724f72e0b3e30
CodeGenTypes
CodeGen
(shl X, cttz(Y)) -> (mul (Y & -Y), X)