Remove segfault test since behavior varies by platform

Author: tmandry

src/test/ui/test-panic-abort.rs

@@ -34,9 +34,3 @@ fn it_fails() {
 fn it_exits() {
     std::process::exit(123);
 }
-
-#[test]
-fn it_segfaults() {
-    let x = unsafe { *(0 as *const u64) };
-    println!("output: {}", x);
-}

src/test/ui/test-panic-abort.run.stdout

@@ -1,9 +1,8 @@
 
-running 5 tests
+running 4 tests
 test it_exits ... FAILED
 test it_fails ... FAILED
 test it_panics ... ok
-test it_segfaults ... ok
 test it_works ... ok
 
 failures:
@@ -26,5 +25,5 @@ failures:
     it_exits
     it_fails
 
-test result: FAILED. 3 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out
+test result: FAILED. 2 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out