[clang] [llvm] demangle function names in trace files (PR #87626)

[Jamie Schmeiser via cfe-commits]

jamieschmeiser wrote:

@rnk It is just a convenience to make things easier to read and should be removed if it is causing compile time issues.  I just happened to see this comment now but will be unavailable for about 2 weeks.  I will take care of it when I return (I'm not ignoring this...)  If you wish to pull it in the mean-time, please go ahead.  Sorry for any inconvenience.

https://github.com/llvm/llvm-project/pull/87626