Rollup merge of #86450 - tmiasko:move-size-limit, r=pnkfelix

Add flag to configure `large_assignments` lint

The `large_assignments` lints detects moves over specified limit.  The
limit is configured through `move_size_limit = "N"` attribute placed at
the root of a crate. When attribute is absent, the lint is disabled.

Make it possible to enable the lint without making any changes to the
source code, through a new flag `-Zmove-size-limit=N`.  For example, to
detect moves exceeding 1023 bytes in a cargo crate, including all
dependencies one could use:

```
$ env RUSTFLAGS=-Zmove-size-limit=1024 cargo build -vv
```

Lint tracking issue #83518.

compiler/rustc_middle/src/middle/limits.rs

@@ -21,7 +21,12 @@ use std::num::IntErrorKind;
 pub fn provide(providers: &mut ty::query::Providers) {
     providers.limits = |tcx, ()| Limits {
         recursion_limit: get_recursion_limit(tcx.hir().krate_attrs(), tcx.sess),
-        move_size_limit: get_limit(tcx.hir().krate_attrs(), tcx.sess, sym::move_size_limit, 0),
+        move_size_limit: get_limit(
+            tcx.hir().krate_attrs(),
+            tcx.sess,
+            sym::move_size_limit,
+            tcx.sess.opts.debugging_opts.move_size_limit.unwrap_or(0),
+        ),
         type_length_limit: get_limit(
             tcx.hir().krate_attrs(),
             tcx.sess,