Rename rustdoc lints to be a tool lint instead of built-in.

- Rename `broken_intra_doc_links` to `rustdoc::broken_intra_doc_links`
- Ensure that the old lint names still work and give deprecation errors
- Register lints even when running doctests

  Otherwise, all `rustdoc::` lints would be ignored.

- Register all existing lints as removed

  This unfortunately doesn't work with `register_renamed` because tool
  lints have not yet been registered when rustc is running. For similar
  reasons, `check_backwards_compat` doesn't work either. Call
  `register_removed` directly instead.

- Fix fallout

  + Rustdoc lints for compiler/
  + Rustdoc lints for library/

Note that this does *not* suggest `rustdoc::broken_intra_doc_links` for
`rustdoc::intra_doc_link_resolution_failure`, since there was no time
when the latter was valid.

src/librustdoc/html/markdown.rs

@@ -21,7 +21,6 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def_id::DefId;
 use rustc_hir::HirId;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::lint;
 use rustc_span::edition::Edition;
 use rustc_span::Span;
 use std::borrow::Cow;
@@ -721,7 +720,7 @@ impl<'tcx> ExtraInfo<'tcx> {
             (None, None) => return,
         };
         self.tcx.struct_span_lint_hir(
-            lint::builtin::INVALID_CODEBLOCK_ATTRIBUTES,
+            crate::core::INVALID_CODEBLOCK_ATTRIBUTES,
             hir_id,
             self.sp,
             |lint| {