Use volatile to prevent heap-to-stack promotion in an ASan test

sandbox/win/src/address_sanitizer_test.cc

Index: sandbox/win/src/address_sanitizer_test.cc
diff --git a/sandbox/win/src/address_sanitizer_test.cc b/sandbox/win/src/address_sanitizer_test.cc
index b88aa81cd43cb12347929962564317c37228a9b5..b4be8bcf7a8850d2df1d1efb699d6fee95299167 100644
--- a/sandbox/win/src/address_sanitizer_test.cc
+++ b/sandbox/win/src/address_sanitizer_test.cc
@@ -40,7 +40,7 @@ SBOX_TESTS_COMMAND int AddressSanitizerTests_Report(int argc, wchar_t** argv) {
   // AddressSanitizer should detect an out of bounds write (heap buffer
   // overflow) in this code.
   volatile int idx = 42;
-  int *blah = new int[42];
+  int *volatile blah = new int[42];
   blah[idx] = 42;
   delete [] blah;
   return SBOX_TEST_FAILED;