Unrolled build for #161112

Rollup merge of #161112 - cuviper:O3, r=saethlin

rustc.1: `-O` is `-C opt-level=3`

This was changed back in 1.86, #135439.

Author: rust-timer

src/doc/man/rustc.1

@@ -62,7 +62,7 @@ Comma separated list of compiler information to print on stdout.
 Equivalent to \fI\-C\ debuginfo=2\fR.
 .TP
 \fB\-O\fR
-Equivalent to \fI\-C\ opt\-level=2\fR.
+Equivalent to \fI\-C\ opt\-level=3\fR.
 .TP
 \fB\-o\fR \fIFILENAME\fR
 Write output to \fIFILENAME\fR. Ignored if multiple \fI\-\-emit\fR outputs are specified which