[clang] nonblocking/nonallocating attributes (was: nolock/noalloc) (PR #84983)

[Doug Wyatt via cfe-commits]

dougsonos wrote:

> So it sounds like the act of adding an additional trailing object will slow down the performance regardless of whether we use the new trailing object?

I was confused by some comments on `FunctionProtoType` which have diverged from the source, and thought that it was necessary to leave Qualifiers as the last trailing object. I have a preliminary run which suggests that by moving the new trailing objects to the end instead of in front of Qualifiers, that will regain some performance.

I also found a hot method to inline. Aiming to open another PR today.


https://github.com/llvm/llvm-project/pull/84983