[llvm] [TextAPI] Track RPaths in the order its provided via command line. (PR #131665)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

It looks like this is causing failures on the reverse-iteration buildbot: https://lab.llvm.org/buildbot/#/builders/110/builds/4558 .  (https://lab.llvm.org/buildbot/#/builders/110/builds/5464 is a more recent build with logs, if you need.)

https://github.com/llvm/llvm-project/pull/131665