Protect std::experimental::optional tests under libcpp-no-exceptions

In these tests there are some paths that explicitly throw, so use
the TEST_THROW macro that was proposed for this and then skip the tests
that may enter the throwing path.

Differential Revision: https://reviews.llvm.org/D26142



git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@286099 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/experimental/optional/optional.object/optional.object.assign/emplace.pass.cpp

@@ -8,7 +8,6 @@
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++98, c++03, c++11
-// XFAIL: libcpp-no-exceptions
 // <optional>
 
 // template <class... Args> void optional<T>::emplace(Args&&... args);
@@ -18,6 +17,8 @@
 #include <cassert>
 #include <memory>
 
+#include "test_macros.h"
+
 using std::experimental::optional;
 
 class X
@@ -48,7 +49,7 @@ class Z
 public:
     static bool dtor_called;
     Z() = default;
-    Z(int) {throw 6;}
+    Z(int) {TEST_THROW(6);}
     ~Z() {dtor_called = true;}
 };
 
@@ -131,6 +132,7 @@ int main()
             assert(Y::dtor_called == true);
         }
     }
+#ifndef TEST_HAS_NO_EXCEPTIONS
     {
         Z z;
         optional<Z> opt(z);
@@ -147,4 +149,5 @@ int main()
             assert(Z::dtor_called == true);
         }
     }
+#endif
 }