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_hir_analysis/src/astconv/mod.rs

@@ -1618,9 +1618,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             let def_span = tcx.def_span(item);
             tcx.dcx()
                 .struct_span_err(span, msg)
-                .code_mv(rustc_errors::error_code!(E0624))
-                .span_label_mv(span, format!("private {kind}"))
-                .span_label_mv(def_span, format!("{kind} defined here"))
+                .with_code(rustc_errors::error_code!(E0624))
+                .with_span_label(span, format!("private {kind}"))
+                .with_span_label(def_span, format!("{kind} defined here"))
                 .emit();
         }
         tcx.check_stability(item, Some(block), span, None);