(libf2c) libu77 struct timezone configuration fix

[craig@jcb-sc.com]

>Craig/Dave -- you may want to forward this to the libf2c folks to avoid
>unnecessary divergence from the libf2c official sources.

No need -- libg2c's libU77 is Dave Love's creation.  There's nothing
equivalent to it in libf2c.  (There's a bit of overlap; libg2c uses
the libU77 versions of dtime_.c and etime_.c, rather than libf2c's
libF77 versions, for example.)

        tq vm, (burley)