Fix match_same_arms in stable_mir

[practicalrs]

Hi,

This PR fixes some clippy warnings

warning: this match arm has an identical body to another arm
   --> compiler/stable_mir/src/mir/visit.rs:197:13
    |
197 | /             StatementKind::FakeRead(_, place) => {
198 | |                 self.visit_place(place, PlaceContext::NON_MUTATING, location);
199 | |             }
    | |_____________^
    |
    = help: try changing either arm body
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_same_arms
help: or try merging the arm patterns
    |
197 |             StatementKind::FakeRead(_, place) | StatementKind::PlaceMention(place) => {
    |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
help: and remove this obsolete arm
    |
209 -             StatementKind::PlaceMention(place) => {
210 -                 self.visit_place(place, PlaceContext::NON_MUTATING, location);
211 -             }
    |

Best regards,
Michal

[rustbot]

r? @celinval

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[rustbot]

This PR changes Stable MIR

cc @oli-obk, @celinval, @ouz-a

[compiler-errors]

Please squash this into one commit.

[practicalrs]

@compiler-errors Here is a new PR #131700 . I guess there is another option to squash commits somewhere in the GH interface. I just did it from the command line and the old PR was closed.

[compiler-errors]

You don't need to open a new PR. You should just force-push to your branch next time.