Rollup merge of #69881 - Centril:fix-69485, r=oli-obk

VariantSizeDifferences: bail on SizeOverflow

Fixes #69485.

r? @oli-obk

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

@@ -0,0 +1,10 @@
+// build-fail
+// only-x86_64
+
+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:5:12
+   |
+LL |     Bug::V([0; !0]);
+   |            ^^^^^^^
+
+error: aborting due to previous error
+