Proposed minor build-process revamp to simplify cross-configuration

[Jeffrey A Law]

 In message < 200005120942.EAA16497@latour.rsch.comm.mot.com >you write:
  > Now, it is interesting to note that 'gcc -Bpath/' alone does almost
  > precisely what we want in order to test the tree before we install
  > into the final location, if and only if, we force all packages being
  > built with gcc to offer some sort of pre-install of headers (and maybe
  > libraries) into a tree structure that mirrors the final tree structure
  > but held within $(obj).  We don't do that today. 
[ ... ]
This is not unlike what Joel & others have proposed for newlib since we
have precisely the same problems there (and some you don't have with
libstdc++ :-)

I think that a make target for installing headers into a well known location
in the build tree which mirrors the structure of the installed tree would
simplify a number of issues.
jeff