llvm-reduce: Change function return types if function is not called (#134035)

Extend the early return on value reduction to mutate the function return
type if the function has no call uses. This could be generalized to rewrite
cases where all callsites are used, but it turns out that complicates the
visitation order given we try to compute all opportunities up front.

This is enough to cleanup the common case where we end up with one
function with a return of an uninteresting constant.

0 files changed, 0 insertions, 0 deletions