Merge changes I52ffa9eb,I0e6e9a76,Ied846201,I84f7a084,I0704cd08, ...

* changes:
  gn2bp: get rid of whole_static_libs hack
  gn2bp: propagate static libs up the tree
  gn2bp: disable rtti in protobufs
  gn2bp: add //base linker scripts
  gn2bp: properly apply -fexceptions
  gn2bp: properly apply -frtti