Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/compiler-rt/test/tsan/free_race2.c

@@ -0,0 +1,26 @@
+// RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
+#include <stdlib.h>
+
+void __attribute__((noinline)) foo(int *mem) {
+  free(mem);
+}
+
+void __attribute__((noinline)) bar(int *mem) {
+  mem[0] = 42;
+}
+
+int main() {
+  int *mem = (int*)malloc(100);
+  foo(mem);
+  bar(mem);
+  return 0;
+}
+
+// CHECK: WARNING: ThreadSanitizer: heap-use-after-free
+// CHECK:   Write of size 4 at {{.*}} by main thread:
+// CHECK:     #0 bar
+// CHECK:     #1 main
+// CHECK:   Previous write of size 8 at {{.*}} by main thread:
+// CHECK:     #0 free
+// CHECK:     #{{1|2}} foo
+// CHECK:     #{{2|3}} main