If you want to cross-compile pcc (from a build machine to a different host machine):
$ export CC=mips-netbsdelf-pcc $ ./configure --host=mips-netbsdelf $ make && make install
This will build pcc into a mipsel binary for running on NetBSD.
redefinition of yytext
Configure tries to detect whether the implementation of lex defines yyext as a char * or char. Since the binary will eventually run on a host machine different to the build machine, configure will test the host version of lex. For this to work properly, you must ensure that libfl.a is available in your cross-compiler environment.