Repeated coercion ICE for an erroring indexing expression since 1.9.

@kennytm

fn f(_: &[f32]) {}
fn main() {
    ()[f(&[1.0])];
}

error: internal compiler error: /checkout/src/librustc_typeck/check/coercion.rs:693:
    expr already has an adjustment on it!

Regressed between 1.8 and 1.9 and found by @kennytm in #40610.
Like #40610, it only happens when there's already an error, possibly from a suggestion attempt.

Meta: perhaps there should be a label for ICE-on-error.

Looks like a double call to check_expr_has_type (

Line 3808 in ccce2c6

self.check_expr_has_type(&idx, self.tcx.types.err);

) introduced in #24475.

Auto merge of #40863 - eddyb:coerce-only-once, r=arielb1

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