Clang: Filter out "#pragma once in main file" warning for headers
Clang: Filter out "#pragma once in main file" warning for headers

This is a libclang bug and unfortunately there is no option to disable
this warning.

Change-Id: I12cdaa0155e7d94a70b8fccd8c9290835704e06b
Task-number: QTCREATORBUG-12067
Reviewed-by: Marco Bubke <5254e489b34ec8bbce36789100e3fc0f41fa62ef@theqtcompany.com>

xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator