Update E0370 to new error code format.

[terrynsun]

Fixes #35634 as part of #35233.

r? @jonathandturner

[rust-highfive]

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[sophiajt]

Thanks for the PR!

Looks like you'll need to run the check and update some of the other unit tests. Since you added a label, it's now showing up in those tests.

---- [compile-fail] compile-fail/discrim-overflow-2.rs stdout ----

error: /build/src/test/compile-fail/discrim-overflow-2.rs:27: unexpected "error": '27:9: 27:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:36: unexpected "error": '36:9: 36:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:45: unexpected "error": '45:9: 45:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:54: unexpected "error": '54:9: 54:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:63: unexpected "error": '63:9: 63:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:72: unexpected "error": '72:9: 72:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:81: unexpected "error": '81:9: 81:13: enum overflowed [E0370]'
error: /build/src/test/compile-fail/discrim-overflow-2.rs:90: unexpected "error": '90:9: 90:13: enum overflowed [E0370]'

You can check this out by running the check and updating the unit tests that fail:

python src/bootstrap/bootstrap.py --step check-cfail --stage 1

[terrynsun]

Thanks! I was having trouble finding the error in the output.