Mark qBadAlloc as [[noreturn]]

So that static analyzers don't get confused by its semantics.
In builds with exceptions disabled, it's not actually called
by client code (e.g. Q_CHECK_PTR will just terminate in that case),
but we still need to make it not return -- add another path that
callss std::terminate(), otherwise we'd have a noreturn function
returning.

Change-Id: Ia8c4ce3e9d971f1757e9c273051cb3dedf23c61f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/global/qglobal.cpp

@@ -3098,7 +3098,11 @@ void qt_check_pointer(const char *n, int l) noexcept
 */
 void qBadAlloc()
 {
+#ifndef QT_NO_EXCEPTIONS
     QT_THROW(std::bad_alloc());
+#else
+    std::terminate();
+#endif
 }
 
 #ifndef QT_NO_EXCEPTIONS

src/corelib/global/qglobal.h

@@ -921,7 +921,7 @@ Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *
 #endif
 
 Q_NORETURN Q_CORE_EXPORT void qt_check_pointer(const char *, int) noexcept;
-Q_DECL_COLD_FUNCTION
+Q_NORETURN Q_DECL_COLD_FUNCTION
 Q_CORE_EXPORT void qBadAlloc();
 
 #ifdef QT_NO_EXCEPTIONS