List all possible optimizations and the optimization level they're
activated at.
.TP
+.BR -q ", " --quiet
+Be less verbose. In particular removes the messages about which files
+are being processed, and which compilation mode is being used, and
+some others. Warnings and errors will of course still be displayed.
+.TP
.BI -W warning "\fR, " "" -Wno- warning
Enable or disable a warning.
.TP