This reapplies 6d263b6f1c (which was reverted in 1c7c6f2b10) with a fix for a CMake issue.
6d263b6f1c
1c7c6f2b10
This reverts commit 6d263b6f1c while I investigate the CMake failures that it causes in some configurations.
Add unit test infrastructure for the ORC runtime, plus a cut-down extensible_rtti system and extensible_rtti unit test. Removes the placeholder.cpp source file. Differential Revision: https://reviews.llvm.org/D102080