[llvm] [LLVMABI] Implement the ABI Typesystem (PR #158329)

[Nikita Popov via llvm-commits]

================

----------------
nikic wrote:

You can use BitmaskEnum.h to add the bitwise operators. It needs a macro `LLVM_MARK_AS_BITMASK_ENUM(/* LargestValue = */ HasFlexibleArrayMember)` in the enum declaration.

https://github.com/llvm/llvm-project/pull/158329