Svinval Extension

5 instructions and 0 pseudo-instructions in the Svinval extension.

• hinval.gvma - Invalidate cached address translations
• hinval.vvma - Invalidate cached address translations
• sfence.inval.ir - Order implicit page table reads after invalidation
• sfence.w.inval - Order writes before sfence
• sinval.vma - Invalidate cached address translations