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.

src/test/ui/async-await/large_moves.attribute.stderr

@@ -1,5 +1,5 @@
 error: moving 10024 bytes
-  --> $DIR/large_moves.rs:10:13
+  --> $DIR/large_moves.rs:12:13
    |
 LL |       let x = async {
    |  _____________^
@@ -17,19 +17,19 @@ LL | #![deny(large_assignments)]
    |         ^^^^^^^^^^^^^^^^^
 
 error: moving 10024 bytes
-  --> $DIR/large_moves.rs:16:14
+  --> $DIR/large_moves.rs:18:14
    |
 LL |     let z = (x, 42);
    |              ^ value moved from here
 
 error: moving 10024 bytes
-  --> $DIR/large_moves.rs:16:13
+  --> $DIR/large_moves.rs:18:13
    |
 LL |     let z = (x, 42);
    |             ^^^^^^^ value moved from here
 
 error: moving 10024 bytes
-  --> $DIR/large_moves.rs:18:13
+  --> $DIR/large_moves.rs:20:13
    |
 LL |     let a = z.0;
    |             ^^^ value moved from here

src/test/ui/async-await/large_moves.option.stderr

@@ -0,0 +1,38 @@
+error: moving 10024 bytes
+  --> $DIR/large_moves.rs:12:13
+   |
+LL |       let x = async {
+   |  _____________^
+LL | |         let y = [0; 9999];
+LL | |         dbg!(y);
+LL | |         thing(&y).await;
+LL | |         dbg!(y);
+LL | |     };
+   | |_____^ value moved from here
+   |
+note: the lint level is defined here
+  --> $DIR/large_moves.rs:1:9
+   |
+LL | #![deny(large_assignments)]
+   |         ^^^^^^^^^^^^^^^^^
+
+error: moving 10024 bytes
+  --> $DIR/large_moves.rs:18:14
+   |
+LL |     let z = (x, 42);
+   |              ^ value moved from here
+
+error: moving 10024 bytes
+  --> $DIR/large_moves.rs:18:13
+   |
+LL |     let z = (x, 42);
+   |             ^^^^^^^ value moved from here
+
+error: moving 10024 bytes
+  --> $DIR/large_moves.rs:20:13
+   |
+LL |     let a = z.0;
+   |             ^^^ value moved from here
+
+error: aborting due to 4 previous errors
+

src/test/ui/async-await/large_moves.rs

@@ -1,8 +1,10 @@
 #![deny(large_assignments)]
 #![feature(large_assignments)]
-#![move_size_limit = "1000"]
+#![cfg_attr(attribute, move_size_limit = "1000")]
 // build-fail
 // only-x86_64
+// revisions: attribute option
+// [option]compile-flags: -Zmove-size-limit=1000
 
 // edition:2018