Using GCC 2.95 as a bootstrap compiler

[Gerald Pfeifer]

Aparently current mainline triggers a bug in GCC 2.95 or we might be
encountering undefined behavior in our PCH-related code?

In any case, some ten days ago (rough estimate) mainline stopped building
both with stock GCC 2.95.3 and the FreeBSD system compiler (GCC 2.95.4) on
i386-unknown-freebsd4.8:

/sw/gcc-2.95.3/bin/gcc   -g  -DIN_GCC   -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long    -DHAVE_CONFIG_H -DGENERATOR_FILE  -o gengtype \
 gengtype.o gengtype-lex.o gengtype-yacc.o ../libiberty/libiberty.a
./gengtype
/sw/test/gcc/cvs/gcc/input.h:27: parse error, unexpected ENT_YACCUNION, expecting GTY_TOKEN
gmake[2]: *** [s-gtype] Error 1
gmake[2]: Leaving directory `/files/pfeifer/OBJ-1031-1155/gcc'
gmake[1]: *** [stage1_build] Error 2

Gerald