* Added a configure check for x86 Bisonx generates x86 assembler which is no good for non-x86 hosts.
If cxxparse is built on/for non-x86 hosts (no, I haven't tried cross compilation) then the bisonx check will fail, which makes distcheck fail, which causes building Debian/Ubuntu packages to fail.
The $host configure test dodges this by omitting bisonx and its tests for non-x86 hosts.