https://reviews.llvm.org/rL340874 replaces lookupFlags with getResponsibilitySet, and this introduces a behaviral change in LegacyJITSymbolResolver::getResponsibilitySet (If there is no existing definition then the caller is responsible for materializing it. https://github.com/llvm-mirror/llvm/blob/master/lib/ExecutionEngine/RuntimeDyld/JITSymbol.cpp#L127). However, this changes is missed from getResponsibilitySetWithLegacyFn. Though I'm not very familiar with Orc code base, I think the behavior of these two functions supposed to match, and the patch actually fixes "symbols not found" error in our codebase using OrcJIT.
twoh: Sorry this sat unreviewed for so long. Is this still hitting you in your codebase, or have you moved over to ORCv2?
Since the current plan is to kill off the legacy ORC stuff in ORCv1 I'm inclined to leave things as-is until we delete this code.