Correct the Macros+inline example expansion
Correct the Macros+inline example expansion

In the whole macro+inline example, I have a feeling that the `arr` reference inside the spliced `sum` step during expansion, should be quoted.
`sum` accepts an Expr in the definition, but at call site `arr` is an Array.
dotty-staging/dotty,sjrd/dotty,lampepfl/dotty,sjrd/dotty,dotty-staging/dotty,lampepfl/dotty,sjrd/dotty,sjrd/dotty,dotty-staging/dotty,lampepfl/dotty,lampepfl/dotty,sjrd/dotty,lampepfl/dotty,dotty-staging/dotty,dotty-staging/dotty