message: Implement f*_fast intrinsics
diff: @@ -987,6 +987,18 @@ fn swap(bcx: &mut FunctionBuilder<'_>, v: Value) -> Value {
  let ret_val = CValue::const_val(fx, ret.layout(), 0);
  ret.write_cvalue(fx, ret_val);
  };
  +
  + fadd_fast | fsub_fast | fmul_fast | fdiv_fast | frem_fast, (c x, c y) {
  + let res = crate::num::trans_float_binop(fx, match intrinsic {
  + "fadd_fast" => BinOp::Add,
  + "fsub_fast" => BinOp::Sub,
  + "fmul_fast" => BinOp::Mul,
  + "fdiv_fast" => BinOp::Div,
  + "frem_fast" => BinOp::Rem,
  + _ => unreachable!(),
  + }, x, y);
  + ret.write_cvalue(fx, res);
  + };
  }
  if let Some((_, dest)) = destination {
  