merge ALU and PQR instructions

[shenghaoyuan]

Hello, Could we merge some ALU and PQR instructions? As they have the same behaviour. If not, could someone please explain why Solana makes this choice?

//ALU32 and ALU64
            ebpf::MUL32_IMM  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = (self.reg[dst] as i32).wrapping_mul(insn.imm as i32)      as u64,
            ebpf::MUL32_REG  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = (self.reg[dst] as i32).wrapping_mul(self.reg[src] as i32) as u64,
            ebpf::DIV32_IMM  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = (self.reg[dst] as u32             / insn.imm as u32)      as u64,
            ebpf::DIV32_REG  if !self.executable.get_sbpf_version().enable_pqr() => {
                throw_error!(DivideByZero; self, self.reg[src], u32);
                                self.reg[dst] = (self.reg[dst] as u32             / self.reg[src] as u32) as u64;
            },
            ebpf::MOD32_IMM  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = (self.reg[dst] as u32             % insn.imm as u32)      as u64,
            ebpf::MOD32_REG  if !self.executable.get_sbpf_version().enable_pqr() => {
                throw_error!(DivideByZero; self, self.reg[src], u32);
                                self.reg[dst] = (self.reg[dst] as u32             % self.reg[src] as u32) as u64;
            },
            
            ebpf::MUL64_IMM  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] =  self.reg[dst].wrapping_mul(insn.imm as u64),
            ebpf::MUL64_REG  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] =  self.reg[dst].wrapping_mul(self.reg[src]),
            ebpf::DIV64_IMM  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] /= insn.imm as u64,
            ebpf::DIV64_REG  if !self.executable.get_sbpf_version().enable_pqr() => {
                throw_error!(DivideByZero; self, self.reg[src], u64);
                                self.reg[dst] /= self.reg[src];
            },

            ebpf::MOD64_IMM  if !self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] %= insn.imm as u64,
            ebpf::MOD64_REG  if !self.executable.get_sbpf_version().enable_pqr() => {
                throw_error!(DivideByZero; self, self.reg[src], u64);
                                self.reg[dst] %= self.reg[src];
            },

//PQR
            ebpf::LMUL32_IMM if self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = (self.reg[dst] as i32).wrapping_mul(insn.imm as i32)      as u64,
            ebpf::LMUL32_REG if self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = (self.reg[dst] as i32).wrapping_mul(self.reg[src] as i32) as u64,
            ebpf::LMUL64_IMM if self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = self.reg[dst].wrapping_mul(insn.imm as u64),
            ebpf::LMUL64_REG if self.executable.get_sbpf_version().enable_pqr() => self.reg[dst] = self.reg[dst].wrapping_mul(self.reg[src]),


            ebpf::UDIV32_IMM if self.executable.get_sbpf_version().enable_pqr() => {
                self.reg[dst] = (self.reg[dst] as u32 / insn.imm as u32)      as u64;
            }
            ebpf::UDIV32_REG if self.executable.get_sbpf_version().enable_pqr() => {
            throw_error!(DivideByZero; self, self.reg[src], u32);
                            self.reg[dst] = (self.reg[dst] as u32 / self.reg[src] as u32) as u64;
            },
            ebpf::UDIV64_IMM if self.executable.get_sbpf_version().enable_pqr() => {
                            self.reg[dst] /= insn.imm as u64;
            }
            ebpf::UDIV64_REG if self.executable.get_sbpf_version().enable_pqr() => {
            throw_error!(DivideByZero; self, self.reg[src], u64);
                            self.reg[dst] /= self.reg[src];
            },
            ebpf::UREM32_IMM if self.executable.get_sbpf_version().enable_pqr() => {
                            self.reg[dst] = (self.reg[dst] as u32 % insn.imm as u32)      as u64;
            }
            ebpf::UREM32_REG if self.executable.get_sbpf_version().enable_pqr() => {
            throw_error!(DivideByZero; self, self.reg[src], u32);
                            self.reg[dst] = (self.reg[dst] as u32 % self.reg[src] as u32) as u64;
            },
            ebpf::UREM64_IMM if self.executable.get_sbpf_version().enable_pqr() => {
                            self.reg[dst] %= insn.imm as u64;
            }
            ebpf::UREM64_REG if self.executable.get_sbpf_version().enable_pqr() => {
            throw_error!(DivideByZero; self, self.reg[src], u64);
                            self.reg[dst] %= self.reg[src];
            },