llvm-project

277069e8 - [Flang] Adjust pass plugin support to match Clang (#174006)

[Flang] Adjust pass plugin support to match Clang (#174006) - Pass plugins can use LLVM options, matching #173287. - Pass plugins can run a hook before codegen, matching #171872. - Pass plugins are now tested whenever they can be built, matching #171998. Plugins currently don't work on AIX, tracked in #172203.