Rename consuming chaining methods on DiagnosticBuilder.

In #119606 I added them and used a `_mv` suffix, but that wasn't great.

A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
  `with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.

The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.

Thanks to @compiler-errors for the suggestion.

compiler/rustc_parse/src/lib.rs

@@ -246,8 +246,8 @@ pub fn parse_cfg_attr(
             match parse_in(parse_sess, tokens.clone(), "`cfg_attr` input", |p| p.parse_cfg_attr()) {
                 Ok(r) => return Some(r),
                 Err(e) => {
-                    e.help_mv(format!("the valid syntax is `{CFG_ATTR_GRAMMAR_HELP}`"))
-                        .note_mv(CFG_ATTR_NOTE_REF)
+                    e.with_help(format!("the valid syntax is `{CFG_ATTR_GRAMMAR_HELP}`"))
+                        .with_note(CFG_ATTR_NOTE_REF)
                         .emit();
                 }
             }