OpenGL function lookup for QNX

Qt no longer supports using OpenGL ES2 via static linkage.

Task-number: QTBUG-60457
Change-Id: I754ff1c084ecdfdf7bea0bd691c8f0fc47a2fcb0
Reviewed-by: Dan Cape <dcape@qnx.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

src/plugins/platforms/qnx/qnx.pro

@@ -78,7 +78,7 @@ qtConfig(opengles2) {
     HEADERS += qqnxglcontext.h \
                qqnxeglwindow.h
 
-    QMAKE_USE += egl
+    QMAKE_USE += opengl_es2 egl
 }
 
 CONFIG(qqnx_pps) {

src/plugins/platforms/qnx/qqnxglcontext.cpp

@@ -47,6 +47,8 @@
 #include <QtGui/QOpenGLContext>
 #include <QtGui/QScreen>
 
+#include <dlfcn.h>
+
 #if defined(QQNXGLCONTEXT_DEBUG)
 #define qGLContextDebug qDebug
 #else
@@ -262,7 +264,10 @@ QFunctionPointer QQnxGLContext::getProcAddress(const char *procName)
         qFatal("QQNX: failed to set EGL API, err=%d", eglGetError());
 
     // Lookup EGL extension function pointer
-    return static_cast<QFunctionPointer>(eglGetProcAddress(procName));
+    QFunctionPointer result = static_cast<QFunctionPointer>(eglGetProcAddress(procName));
+    if (!result)
+        result = reinterpret_cast<QFunctionPointer>(dlsym(RTLD_DEFAULT, procName));
+    return result;
 }
 
 bool QQnxGLContext::isSharing() const