Needed for the test_app_server.
The logic here may need some improvements, but I'm not sure how to find
the right library name in all cases. I fixed at least the x86_gcc2 case
here.
* This stage builds the gcc packages to get the shared syslibs, which
only requires the Haiku glue code.
* Add separate declaration section for stage0 packages to
HaikuPortsCross repository files.
* For the bootstrap_stage0 platform, fall back to the gcc headers
provided by the cross-compiler.
* This file contains jam rules for getting the different versions
of libgcc, libsupc++ and libstdc++ used throughout Haiku's
build system.
* Additionally, there are rules for accessing the c++ headers
and the gcc headers.
* These rules are included by Jamrules, but not yet used anywhere.
