Rollup merge of #25807 - rillian:manpages, r=alexcrichton

Quick update to fix two manpage issues I noticed in #25689.

man/rustc.1

@@ -1,4 +1,4 @@
-.TH RUSTC "1" "March 2014" "rustc 0.13.0" "User Commands"
+.TH RUSTC "1" "August 2015" "rustc 1.2.0" "User Commands"
 .SH NAME
 rustc \- The Rust compiler
 .SH SYNOPSIS
@@ -160,7 +160,7 @@ If the value is 'help', then a list of available CPUs is printed.
 \fBtarget\-feature\fR='\fI+feature1\fR,\fI\-feature2\fR'
 A comma\[hy]separated list of features to enable or disable for the target.
 A preceding '+' enables a feature while a preceding '\-' disables it.
-Available features can be discovered through \fItarget\-cpu=help\fR.
+Available features can be discovered through \fIllc -mcpu=help\fR.
 .TP
 \fBpasses\fR=\fIval\fR
 A space\[hy]separated list of extra LLVM passes to run.

man/rustdoc.1

@@ -1,4 +1,4 @@
-.TH RUSTDOC "1" "March 2014" "rustdoc 0.13.0" "User Commands"
+.TH RUSTDOC "1" "August 2015" "rustdoc 1.2.0" "User Commands"
 .SH NAME
 rustdoc \- generate documentation from Rust source code
 .SH SYNOPSIS