EPIC: Public VM

[kevaundray]

Tracking tasks

• Change Brillig to be memory-only (no registers) #4158
• Use CallData and ReturnData for params/returns instead of memory #4159
• Add CAST opcodes to program type conversions #4160
• Bit sizes in brillig binary operations should match the bit sizes of the operands #4369
• Only use u32s for memory addresses #4161
• Support restricted bit sizes in noir: just support 1, 8, 32, 64, field #4162
• Support SET opcode – SET (size: 8, 16, 32, 64, 128, not field). The SET opcode is currently being called Const in Brillig.
• Add CAST opcode that solely does type conversions
• JUMPIF to treat the conditional predicate as an integer and just check for zeroness instead of treating it a sa boolean
• Add CMOV instruction #4580
• Convert signed division to unsigned arithmetic
• Compile all public functions in a contract into a single bytecode blob with a jump table