Fix a few instances of missing PYOPENCL_CL_CASTABLE_THIS

src/c_wrapper/gl_obj.cpp

@@ -15,9 +15,9 @@ gl_texture::get_gl_texture_info(cl_gl_texture_info param_name) const
 {
     switch (param_name) {
     case CL_GL_TEXTURE_TARGET:
-        return pyopencl_get_int_info(GLenum, GLTexture, this, param_name);
+        return pyopencl_get_int_info(GLenum, GLTexture, PYOPENCL_CL_CASTABLE_THIS, param_name);
     case CL_GL_MIPMAP_LEVEL:
-        return pyopencl_get_int_info(GLint, GLTexture, this, param_name);
+        return pyopencl_get_int_info(GLint, GLTexture, PYOPENCL_CL_CASTABLE_THIS, param_name);
     default:
         throw clerror("MemoryObject.get_gl_texture_info", CL_INVALID_VALUE);
     }

src/c_wrapper/memory_object.cpp

@@ -51,7 +51,7 @@ memory_object::get_info(cl_uint param_name) const
 #endif
 #if PYOPENCL_CL_VERSION >= 0x2000
     case CL_MEM_USES_SVM_POINTER:
-        return pyopencl_get_int_info(cl_bool, MemObject, this, param_name);
+        return pyopencl_get_int_info(cl_bool, MemObject, PYOPENCL_CL_CASTABLE_THIS, param_name);
 #endif
 
     default: