Fix most GCC test failures.

This patch fixes almost all currently failing tests when
using GCC ToT.

The specific changes are:

(A) Workaround gcc.gnu.org/PR83921 which rejects variables w/o initializers
in constexpr contexts -- even when the variable is an empty class. This
bug has been worked around at all callsites by adding an initializer.
Additionally a new test, constexpr_init.pass.cpp, has been added to
test that Clang doesn't suffer from these bugs.

(B) Fix streambuf.assign/swap.pass.cpp. This test was never actually
calling the swap method as intended. In fact, the swap function it
intended to call was ill-formed when instantiated. GCC diagnosed
this ill-formedness w/o needing an instantiation.

(C) size_delete11.pass.cpp was fixed by adding c++2a to the list of
unsupported dialects.

llvm-svn: 322810

1 files changed, 1 insertions, 1 deletions

diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete11.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete11.pass.cpp
index 945bf779a89..3d947de426d 100644
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete11.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete11.pass.cpp
@@ -12,7 +12,7 @@
 // Note that sized delete operator definitions below are simply ignored
 // when sized deallocation is not supported, e.g., prior to C++14.
 
-// UNSUPPORTED: c++14, c++17
+// UNSUPPORTED: c++14, c++17, c++2a
 // UNSUPPORTED: sanitizer-new-delete
 
 #include <new>