* Migrate most of our tests to use `split-file` instead of `echo`
* Remove individual `rm -f %t/libfoo.a` commands in favor of a top-level `rm -rf %t`
* Remove unused `Inputs/libfunction.s`
Reviewed By: #lld-macho, compnerd
Differential Revision: https://reviews.llvm.org/D93604
Needed for testing Objective-C programs (since e.g. Core
Foundation is a framework)
Reviewed By: #lld-macho, compnerd
Differential Revision: https://reviews.llvm.org/D83925