we correctly check that the perm is not lazy when triggering protectors

src/tools/miri/tests/pass/tree_borrows/protected_uninit.rs

@@ -0,0 +1,16 @@
+//@compile-flags: -Zmiri-tree-borrows
+
+// Protectors should not trigger on uninitialized locations,
+// otherwise we can write safe code that triggers UB.
+// To test this we do a write access that disables a protected
+// location, but the location is actually outside of the protected range.
+
+// Both x and y are protected here
+fn write_second(_x: &mut u8, y: &mut u8) {
+    *y = 1;
+}
+
+fn main() {
+    let mut data = (0u8, 1u8);
+    write_second(&mut data.0, &mut data.1);
+}