VariantSizeDifferences: bail on SizeOverflow

src/librustc_lint/types.rs

@@ -998,10 +998,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for VariantSizeDifferences {
             let ty = cx.tcx.erase_regions(&t);
             let layout = match cx.layout_of(ty) {
                 Ok(layout) => layout,
-                Err(ty::layout::LayoutError::Unknown(_)) => return,
-                Err(err @ ty::layout::LayoutError::SizeOverflow(_)) => {
-                    bug!("failed to get layout for `{}`: {}", t, err);
-                }
+                Err(ty::layout::LayoutError::Unknown(_))
+                | Err(ty::layout::LayoutError::SizeOverflow(_)) => return,
             };
             let (variants, tag) = match layout.variants {
                 layout::Variants::Multiple {

src/test/ui/lint/issue-69485-var-size-diffs-too-large.rs

@@ -0,0 +1,9 @@
+// build-fail
+
+fn main() {
+    Bug::V([0; !0]); //~ ERROR is too big for the current
+}
+
+enum Bug {
+    V([u8; !0]),
+}

src/test/ui/lint/issue-69485-var-size-diffs-too-large.stderr

@@ -0,0 +1,8 @@
+error: the type `[u8; 18446744073709551615]` is too big for the current architecture
+  --> $DIR/issue-69485-var-size-diffs-too-large.rs:4:12
+   |
+LL |     Bug::V([0; !0]);
+   |            ^^^^^^^
+
+error: aborting due to previous error
+