A major change in 3.7.x is that the .c files generated by bison now
include the .h file generated by "bison -d". Makefiles that rename
the generated .h file will run into problems unless they also edit
the .c file to match. Alternately, the --defines=foo.h option can
be used instead of -d to specify the desired header file name.
With help from naddy@ OK sthen@
adbc25336d