ZJIT: Split CPush to support pushing immediates

Author: tekknolagi

zjit/src/backend/arm64/mod.rs

@@ -675,6 +675,10 @@ impl Assembler
                     *opnd = opnd0;
                     asm.push_insn(insn);
                 },
+                Insn::CPush(opnd) => {
+                    let opnd = split_load_operand(asm, *opnd);
+                    asm.push_insn(Insn::CPush(opnd));
+                }
                 Insn::Store { dest, src } => {
                     // The value being stored must be in a register, so if it's
                     // not already one we'll load it first.