QNX: fix compilation with C++11 enabled

QNX uses GCC, but by default not libstdc++ as the standard library,
but 'libcpp', a Dinkumware-derived implementation that doesn't sport
many of the C++11 features, yet.

Thus, the compiler detection sets Q_COMPILER_INITIALIZER_LIST, which is true,
in a way, but we're lacking stdlib support, so the next
  \#include <initializer_list> will fail.

So, simply don't define Q_COMPILER_INITIALIZER_LIST if we're on QNX
and detect a Dinkumware signature (taken from Boost.Config).

This is a hot-fix. I'm also preparing a more comprehensive solution
(qstdlibdetection.h).

Change-Id: Ieeb147251c2935517faba61f75d1580a9e1649c4
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

src/corelib/global/qcompilerdetection.h

@@ -661,6 +661,18 @@
 //#      define Q_COMPILER_INITIALIZER_LISTS
 #endif
 
+#if defined(Q_OS_BLACKBERRY) || defined(Q_OS_QNX)
+#  include <utility>
+#  if defined(_YVALS) || defined(_LIBCPP_VER)
+// QNX: libcpp (Dinkumware-based) doesn't have the <initializer_list>
+// header, so the feature is useless, even if the compiler supports
+// it. Disable.
+#    ifdef Q_COMPILER_INITIALIZER_LISTS
+#      undef Q_COMPILER_INITIALIZER_LISTS
+#    endif
+#  endif
+#endif // Q_OS_BLACKBERRY || Q_OS_QNX
+
 /*
  * C++11 keywords and expressions
  */