[clang] [clang] Add test for CWG1350 (PR #78040)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

I was way too deep into P0136R1 [Rewording inheriting constructors (core issue 1941 et al)](https://wg21.link/p0136r1) when I realized Richard has written tests for all issues covered there long ago. So I decided to carry on and check whether those tests would benefit from additional test cases. That's how I came up with a new test case for CWG1573, and came about its related issue 1350, which was lacking a test.

https://github.com/llvm/llvm-project/pull/78040