ErrorOrTest.cpp: Check existence of EXPECT_DEBUG_DEATH. It is not always available.

llvm-svn: 173123
diff --git a/llvm/unittests/Support/ErrorOrTest.cpp b/llvm/unittests/Support/ErrorOrTest.cpp
index 3181b4f..b30895c 100644
--- a/llvm/unittests/Support/ErrorOrTest.cpp
+++ b/llvm/unittests/Support/ErrorOrTest.cpp
@@ -28,7 +28,9 @@
   a = t2();
   EXPECT_FALSE(a);
   EXPECT_EQ(errc::invalid_argument, a);
+#ifdef EXPECT_DEBUG_DEATH
   EXPECT_DEBUG_DEATH(*a, "Cannot get value when an error exists");
+#endif
 }
 
 #if LLVM_HAS_CXX11_STDLIB