[libFuzzer] Change sig-trap test to allow expected output strings in any order (llvm#157407)

I have seen some flakiness in this test where the 2 checked strings
appear in a different order. Due to buffering of writes, and that one of
these strings is written during the signal handler, I think this is
valid.

This PR relaxes the test to allow those strings to appear in
either order.

(cherry picked from commit d685508)

Author: DanBlackwell

compiler-rt/test/fuzzer/sig-trap.test

@@ -5,7 +5,7 @@ UNSUPPORTED: target={{.*windows.*}}
 RUN: %cpp_compiler %S/SigTrapTest.cpp -o %t
 
 RUN: not %run %t            2>&1 | FileCheck %s
-CHECK: BINGO
-CHECK: ERROR: libFuzzer: deadly signal
+CHECK-DAG: BINGO
+CHECK-DAG: ERROR: libFuzzer: deadly signal
 
 RUN: trap "%run %t -handle_trap=0" TRAP