.pro parser does not implement write_file, leading to incomplete parse

Steps to reproduce:
Configure qt with a C++11 capable toolchain.
Open qtdeclarative.pro, notice that any C++11 code is flagged as a error.

The cause of that is in qtmodule_prf, where the line

contains(QT_CONFIG, c++11):CONFIG += c++11

is not reached because the line aborts

write_file($$MODULE_PRI, MODULE_PRI_CONT)|error("Aborting.")

stops the evaluation.