llvm-project

f94c4815 - [clang] Track source deduction guide for alias template deduction guides (#123875)

[clang] Track source deduction guide for alias template deduction guides (#123875) For deduction guides generated from alias template CTAD, store the deduction guide they were originated from. The source kind is also maintained for future expansion in CTAD from inherited constructors. This tracking is required to determine whether an alias template already has a deduction guide corresponding to some deduction guide on the original template, in order to support deduction guides for the alias from deduction guides declared after the initial usage.