test: Remove sanitizer-thread test

Unfortunately it appears to spuriously fail so we can't gate on it

src/test/run-make/sanitizer-thread/Makefile

@@ -1,10 +0,0 @@
--include ../tools.mk
-
-ifdef SANITIZER_SUPPORT
-all:
-	$(RUSTC) -g -Z sanitizer=thread -Z print-link-args racy.rs | grep -q librustc_tsan
-	$(TMPDIR)/racy 2>&1 | grep -q 'data race'
-else
-all:
-
-endif

src/test/run-make/sanitizer-thread/racy.rs

@@ -1,21 +0,0 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use std::thread;
-
-static mut ANSWER: i32 = 0;
-
-fn main() {
-    let t1 = thread::spawn(|| unsafe { ANSWER = 42 });
-    unsafe {
-        ANSWER = 24;
-    }
-    t1.join().ok();
-}