illumos gate

uts/intel/sys/tss.h defines the structures for the Task-State Structure from the Intel Architecture. Currently the tss structure is only defined depending on the architecture that you're on. Consumers such as VMMs have use of this structure outside of the architecture specific version. To this end, we should expose the 64-bit and 32-bit versions as different structs and maintain backwards compatibility by ensuring that struct tss is always correct for the compilation environment. While we're here we should also add the 16-bit version of the tss structure.