LibJS/JIT: Use mov() helper in Assembler::native_call()

Author: https://github.com/awesomekling
Commit: 1e8c6d3b06
Pull-request: https://github.com/SerenityOS/serenity/pull/21619
Reviewed-by: https://github.com/Hendiadyoin1

Userland/Libraries/LibJS/JIT/Assembler.h

@@ -396,10 +396,10 @@ struct Assembler {
         // align the stack to 16-byte boundary
         sub(Operand::Register(Reg::RSP), Operand::Imm8(8));
 
-        // load callee into RAX and make indirect call
+        // load callee into RAX
-        emit8(0x48);
+        mov(Operand::Register(Reg::RAX), Operand::Imm64(bit_cast<u64>(callee)));
-        emit8(0xb8);
+
-        emit64((u64)callee);
+        // call RAX
         emit8(0xff);
         emit8(0xd0);