[llvm] [BranchFolding] Add an option to tail merge only bbs without successors (PR #101969)

[Vladimir Radosavljevic via llvm-commits]

vladimirradosavljevic wrote:

> > @wangpc-pp I have added test case. I'm working on a downstream target and we are not using llvm-testsuite, so I can't pull benchmark numbers. Can this be merged without benchmark numbers?
> 
> You'd better provide some data since we can't see the tatal gain from this patch, and I think it can be very easy, you just need to compile llvm-test-suite twice (w and w/o this newly-added option) and compare the code size. You may refer to this doc: https://llvm.org/docs/TestSuiteGuide.html. :-)

Since downstream architecture is a VM, currently I'm not able to run any C or C++ program, thus can't run llvm-testsuite.

https://github.com/llvm/llvm-project/pull/101969