Provides -p as a short alias for -pretty-print. Motivation: https://bugs.llvm.org/show_bug.cgi?id=40076
Thanks for working on this!
Nit, here and in the line above we're being inconsistent with the number of '-' characters used to prefix options (single dash for llvm-symbolizer, double for FileCheck). It would be nice if they were consistent. I have a marginal preference for double dash, but I don't mind if you want to go the other way.
It looks like this line needs clang-formatting.
Aliases aren't in the help text by default, but you can make them be by adding the cl::NotHidden attribute. I think you should do that.
I'm not sure I understand what you mean? I think that there was no good reason to use a mixture of single and double dashes before.
You can change the other lines in the test to make them all match.