[LLVM][LICM] Stack overflow after 469702c

[pifon2a]

[LICM] Sink unused l-invariant loads in preheader. (#157559) increases the stack usage significantly.

Reproducer:

ulimit -s 200
opt -passes="licm"  ~/workspace/licm-repro.ll -f

if the PR is rolled back, then it works even with a smaller stack size ulimit -s 64.

licm-repro.zip