The previous uses of this symbol were all in wordsize-32 code.
In commit eeddfa91cbb1 ("Consolidate off_t/off64_t syscall
argument passing") it was expanded to be used in pread/pwrite.
Accordingly, we only define it in 32-bit compilation modes now.
Both tilepro and tilegx32 follow this convention for the
kernel ABI. tilegx64 follows it for passing 128-bit values,
but there are no such ABIs in the kernel.