When building with an experiment activated, the generated
instantiate-<experimentname>.ah gets included in each and every FAIL*
translation unit including Bochs's ones. In the case of the
generic-experiment (and probably many others), this indirectly included
Google protobuf headers, which failed to compile for Bochs's gui/wx.cc and
gui/x.cc: The included X headers pollute the preprocessor namespace by
an internal protobuf "Status" class.
Change-Id: I613f5c792a9519cf2573eddc7fef6266c7168494