Fix VPATH builds by gathering up more paths where objects might be located.
Fix VPATH builds by gathering up more paths where objects might be
located.

* build/gen_base.py (_GeneratorBase.__init__): look at the sources
    patterns for relative paths.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@842364 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion