FreeBSD: TSan: main thread finished with ignores enabled

Disabling several TSan tests that are failing due to a bug in the thread
sanitizer. TSan appears to be setting the thread to ignored in the
`thr_exit` interceptor, and then immediately checking that the thread
isn't being ignored, and dying.

```
ThreadSanitizer: main thread finished with ignores enabled
  One of the following ignores was not ended (in order of probability)
```

rdar://158450231

Author: etcwilde

test/Sanitizers/tsan/async_taskgroup_next.swift

@@ -6,6 +6,12 @@
 // REQUIRES: tsan_runtime
 // UNSUPPORTED: use_os_stdlib
 
+// Bug in TSan on FreeBSD
+// Thread destruction interceptor marks the thread ignored and then checks that
+// the thread isn't being ignored.
+// rdar://158450231
+// XFAIL: OS=freebsd
+
 var scratchBuffer: UnsafeMutableBufferPointer<Int> = .allocate(capacity: 1000)
 
 @available(SwiftStdlib 5.1, *)

test/Sanitizers/tsan/basic_future.swift

@@ -6,6 +6,12 @@
 // REQUIRES: tsan_runtime
 // UNSUPPORTED: use_os_stdlib
 
+// Bug in TSan on FreeBSD
+// Thread destruction interceptor marks the thread ignored and then checks that
+// the thread isn't being ignored.
+// rdar://158450231
+// XFAIL: OS=freebsd
+
 import Dispatch
 
 #if canImport(Darwin)

test/Sanitizers/tsan/mainactor.swift

@@ -7,6 +7,12 @@
 // UNSUPPORTED: use_os_stdlib
 // UNSUPPORTED: threading_none
 
+// Bug in TSan on FreeBSD
+// Thread destruction interceptor marks the thread ignored and then checks that
+// the thread isn't being ignored.
+// rdar://158450231
+// XFAIL: OS=freebsd
+
 import Dispatch
 
 /// @returns true iff the expected answer is actually the case, i.e., correct.

test/Sanitizers/tsan/norace-task-group-cancellation.swift

@@ -7,6 +7,12 @@
 // UNSUPPORTED: back_deployment_runtime
 // UNSUPPORTED: use_os_stdlib
 
+// Bug in TSan on FreeBSD
+// Thread destruction interceptor marks the thread ignored and then checks that
+// the thread isn't being ignored.
+// rdar://158450231
+// XFAIL: OS=freebsd
+
 @main
 public struct TSANDataRaceOnCancel {
   public static func main() async throws {

validation-test/Sanitizers/tsan-inout.swift

@@ -8,6 +8,12 @@
 // REQUIRES: stress_test
 // REQUIRES: tsan_runtime
 
+// Bug in TSan on FreeBSD
+// Thread destruction interceptor marks the thread ignored and then checks that
+// the thread isn't being ignored.
+// rdar://158450231
+// XFAIL: OS=freebsd
+
 // Test ThreadSanitizer execution end-to-end when calling
 // an uninstrumented module with inout parameters