large_assignments: Add test for -Zinline-mir

Author: Enselic

tests/ui/lint/large_assignments/inline-mir.rs

@@ -0,0 +1,24 @@
+#![feature(large_assignments)]
+#![deny(large_assignments)]
+#![move_size_limit = "1000"]
+
+//! Tests that with `-Zinline-mir`, we do NOT get an error that points to the
+//! implementation of `UnsafeCell` since that is not actionable by the user:
+//!
+//! ```text
+//! error: moving 9999 bytes
+//!   --> /rustc/FAKE_PREFIX/library/core/src/cell.rs:2054:9
+//!    |
+//!    = note: value moved from here
+//! ```
+//!
+//! We want the diagnostics to point to the relevant user code.
+
+//@ build-fail
+//@ compile-flags: -Zmir-opt-level=1 -Zinline-mir
+
+pub fn main() {
+    let data = [10u8; 9999];
+    let cell = std::cell::UnsafeCell::new(data); //~ ERROR large_assignments
+    std::hint::black_box(cell);
+}

tests/ui/lint/large_assignments/inline-mir.stderr

@@ -0,0 +1,15 @@
+error: moving 9999 bytes
+  --> $DIR/inline-mir.rs:22:43
+   |
+LL |     let cell = std::cell::UnsafeCell::new(data);
+   |                                           ^^^^ value moved from here
+   |
+   = note: The current maximum size is 1000, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
+note: the lint level is defined here
+  --> $DIR/inline-mir.rs:2:9
+   |
+LL | #![deny(large_assignments)]
+   |         ^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+