- add names to mmu registers, this helps understanding the code which
uses/modifies them.
- fold i/d mmu tlb entries tag and tte arrays into arrays of tlb entries
- extract demap_tlb routine (code duplication)
- extract replace_tlb routine (code duplication)

- flush qemu tlb translations when replacing sparc64 mmu tlb entries

I have no test case which demands flushing qemu translations,
and this patch should have no other visible changes to runtime.

Signed-off-by:  <igor.v.kovalenko@gmail.com>

--
Kind regards,
Igor V. Kovalenko