[llvm] [flang-rt] Optimise ShallowCopy and use it in CopyInAssign (PR #140569)

[Kajetan Puchalski via llvm-commits]

mrkajetanp wrote:

> This change seems to have broken building unittests for me

I can't seem to reproduce it, including on Gentoo amd64. Do you maybe have more details on how it breaks?


https://github.com/llvm/llvm-project/pull/140569