[debuginfo-tests] Recommit test sret.cpp This test was accidently removed when the directory structure was shuffled around for dexter in f78c236efda8. Reviewed By: aprantl Differential Revision: https://reviews.llvm.org/D96968 GitOrigin-RevId: 54b6d01685ef3b3bce4f0b1e9262291a9d535725