llvm-foreach should print the full command when failing

[sarnex]

Is your feature request related to a problem? Please describe

Right now we get errors like

llvm-foreach: No such file or directory

which is not helpful at all. If it printed the entire command it tried to run that failed, it would be much more useful

Describe the solution you would like

No response

Describe alternatives you have considered

No response

Additional context

No response