Add opcodes for cursor operations.
Fix instruction encodings for cursor ops.
Add missing CIncCursor / CSetCursor as different operations.
Add pattern for matching CIncCursor.
Add intrinsics for cursor-related functions.
s/cursor/offset in the cursor-related code.
Cursors, as exposed in the ISA, are offsets within a capability.  Before we end up with lots of asm that uses them, change the mnemonics to more accurately reflect their use / behaviour.
Rename MIPS intrinsics to also use offset instead of cursor.
[cheri] Fix the CHERI range checker to (most) work again now that address space casts are a common way of constructing capabilities.
Nice error rather than assert failure on some invalid asm.
Make CHERI addressing mode folder work with the code generated for cap cursors.