Fix some misbehaving tests

Author: varkor

src/test/run-pass/binding/empty-types-in-patterns.rs

@@ -14,6 +14,7 @@
 #![feature(slice_patterns)]
 #![allow(unreachable_patterns)]
 #![allow(unreachable_code)]
+#![allow(unused_variables)]
 
 #[allow(dead_code)]
 fn foo(z: !) {

src/test/run-pass/issues/issue-41696.rs

@@ -11,6 +11,7 @@
 // run-pass
 #![allow(dead_code)]
 #![allow(unused_variables)]
+#![recursion_limit = "128"]
 // this used to cause exponential code-size blowup during LLVM passes.
 
 #![feature(test)]

src/test/ui/consts/const-eval/ub-uninhabit.stderr

@@ -1,21 +1,21 @@
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-uninhabit.rs:13:1
+  --> $DIR/ub-uninhabit.rs:14:1
    |
 LL | const BAD_BAD_BAD: Bar = unsafe { (TransmuteUnion::<(), Bar> { a: () }).b };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a value of an uninhabited type
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-uninhabit.rs:16:1
+  --> $DIR/ub-uninhabit.rs:17:1
    |
 LL | const BAD_BAD_REF: &Bar = unsafe { mem::transmute(1usize) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a value of an uninhabited type at .<deref>
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-uninhabit.rs:19:1
+  --> $DIR/ub-uninhabit.rs:20:1
    |
 LL | const BAD_BAD_ARRAY: [Bar; 1] = unsafe { (TransmuteUnion::<(), [Bar; 1]> { a: () }).b };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a value of an uninhabited type