[clang] [Clang] Preserve CXXParenListInitExpr in TreeTransform. (PR #138518)

[Erich Keane via cfe-commits]

https://github.com/erichkeane approved this pull request.

Please change the commit message to do Fixes #<whatever> instead of the reverse, so this actually closes the bug :) 

https://github.com/llvm/llvm-project/pull/138518