[ASan/Win] Add a test case for r208215 [stack buffer overflow in <iostream>]

The issue re-appears if one uses the -fsanitize-blacklist= flag,
so it's time to have a test case.

llvm-svn: 227799

compiler-rt/test/asan/TestCases/Windows/iostream_sbo.cc

@@ -0,0 +1,13 @@
+// RUN: %clang_cl_asan -O0 %s -Fe%t
+// RUN: echo "42" | %run %t 2>&1 | FileCheck %s
+
+#include <iostream>
+
+int main() {
+  int i;
+  std::cout << "Type i: ";
+  std::cin >> i;
+  return 0;
+// CHECK: Type i:
+// CHECK-NOT: AddressSanitizer: stack-buffer-overflow on address [[ADDR:0x[0-9a-f]+]]
+}