Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/compiler-rt/test/ubsan/TestCases/Misc/deduplication.cpp

@@ -0,0 +1,26 @@
+// RUN: %clangxx -fsanitize=undefined %s -o %t && %run %t 2>&1 | FileCheck %s
+// Verify deduplication works by ensuring only one diag is emitted.
+#include <limits.h>
+#include <stdio.h>
+
+void overflow() {
+  int i = INT_MIN;
+  --i;
+}
+
+int main() {
+  // CHECK: Start
+  fprintf(stderr, "Start\n");
+  fflush(stderr);
+
+  // CHECK: runtime error
+  // CHECK-NOT: runtime error
+  // CHECK-NOT: runtime error
+  overflow();
+  overflow();
+  overflow();
+
+  // CHECK: End
+  fprintf(stderr, "End\n");
+  return 0;
+}