[clang] [CIR] Call code gen; create empty cir.func op (PR #113483)

[David Olsen via cfe-commits]

dkolsen-pgi wrote:

> Is it at all possible to write a test to exercise the new functionality,

Yes, I am planning to write a CIR code gen test as part of this PR, to verify that a `cir.func` op is created.  But there is some broken or missing functionality that I need to fix first before I can even write the test.


https://github.com/llvm/llvm-project/pull/113483