pgindent vs. pgperltidy command-line arguments

Until PG15, calling pgindent without arguments would process the whole 
tree.  Now you get

No files to process at ./src/tools/pgindent/pgindent line 372.

Is that intentional?


Also, pgperltidy accepts no arguments and always processes the whole 
tree.  It would be nice if there were a way to process individual files 
or directories, like pgindent can.

Attached is a patch for this.

(It seems that it works ok to pass regular files (not directories) to 
"find", but I'm not sure if it's portable.)