Rollup merge of #157592 - ariagivens:suggest-comma-multiple, r=JonathanBrouwer

Suggest comma multiple

Following from rust-lang/rust#157545

If there are multiple missing comma's, suggest fixing all of them in one step to avoid error cascade.

For example:
```
error: attribute items not separated with `,`
   |
LL |     name = "name"
   |                  ^ help: try adding `,` here
```
followed by
```
error: attribute items not separated with `,`
   |
LL |     kind = "static"
   |                    ^ help: try adding `,` here
```
after adding the comma.

Now this becomes one error:
```
error: attribute items not separated with `,`
  --> $DIR/attr-missing-comma.rs:10:18
   |
LL |     name = "name"
   |                  ^
   |
help: try adding `,` here
   |
LL |     name = "name",
   |                  +
help: try adding `,` here
   |
LL |     kind = "static",
   |                    +
```