[clang] Add some CodeGen tests for CWG 2xx issues (#80823)

This patch covers CWG issues
[201](https://cplusplus.github.io/CWG/issues/201.html),
[210](https://cplusplus.github.io/CWG/issues/210.html),
[292](https://cplusplus.github.io/CWG/issues/292.html).

[CWG208](https://cplusplus.github.io/CWG/issues/208.html) is not
covered, as it actually requires a libcxxabi test.

Resolution of CWG292 has been superseded by
[P0145R3](https://wg21.link/p0145r3) "Refining Expression Evaluation
Order for Idiomatic C++"
(see changes to paragraph 5.3.4/18).