Log Message:
1) Locate adalib for bootstrap compiler with ${ALT_GCC} --print-file-name=adalib
   rather than find. This behaves better if ${ALT_GCC} does not specify
   a gcc executable.
2) Change to uniform handling of ABI baseline-pairs for NetBSD. There
   must be agreement between the Makefile and libstdc++-v3/configure.host;
   this change ensures consistency by introducing ABI_BASELINE_PAIR
   variable used in both.
3) Bump revision number.