For some reason, whenever OSMajorVersion was >= 2 (this equates to a
2.x kernel or above), yacc would be used instead of bison.
On Ubuntu, and probably other linux systems, yacc is just a shell
wrapper around bison, so let's just use that directly.
#define MkdirHierCmd mkdir -p
#define CppCmd /lib/cpp
-#if OSMajorVersion >= 2
-# define YaccCmd yacc
-#else
-# define YaccCmd bison -y
-#endif
+#define YaccCmd bison -y
#define LexCmd flex -l
#define LexLib -lfl
#define PreProcessCmd CcCmd -E