Following up here it seems like all the ioctls that at least now all these are defined in /usr/include/asm-generic. They should be the same for all Linux ISAs. I don't know if this was always the case, but it seems reasonable that the issue here was Tru64 vs Linux.

I don't think that's true. From an email I wrote about this on the 29th of last month:

As far as the ioctl patch, I suspect the reason Vince Weaver wanted to
nuke the cases present in ioctlFunc is that the constants they rely on
don't exist in x86. They're defined for Alpha, MIPS, SPARC and powerpc,
and in the file that uses them in the kernel (drivers/tty/tty_ioctl.c)
conditionally compiles in the code that implements those calls based on
if the constant is defined. Attaching the ioctl functions breaks the
build because those constants aren't defined, and they aren't defined
because there's nothing to set them to.

However, if you go on your favorite x86 machine and take a look at include:
linux/ioctl.h includes x86_64-linux-gnu/asm/ioctl.h which includes asm-generic/ioctls.h 
the latter of which defines all those things like TCGETS