[llvm] [BPF] lowering target address leaf nodes tconstpool (PR #73667)

[via llvm-commits]

eddyz87 wrote:

The code lgtm.
Constants pool usage matches other backends (e.g. x86) and #73668 triggers code paths from this MR.
It seems that there is no straightforward way to test this commit: all uses of getConstantPool/getTargetConstantPool I checked are internal to DAG translation of specific constructs.
It might be possible to make a unit test that constructs DAG and lowers it, but I think that's an overkill.

@yonghong-song , wdyt?

https://github.com/llvm/llvm-project/pull/73667