[InferAddressSpaces] Register pass. (#65639)

InferAddressSpaces failed to call its initialization function. It was
still called through initializeScalarOpts in llc and opt, but it was
skipped entirely in clang. When the initialization function is not
called, this results in confusing behavior where the pass appears to
run, but not entirely as it should, e.g. the pass is excluded from
-print-before-all and -print-after-all.