Migrate rustc_builtin_macros to SessionDiagnostic

[str4d]

Part of #100717.

[rust-highfive]

r? @oli-obk

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[rust-log-analyzer]

The job mingw-check failed! Check out the build log: (web) (plain)

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configure: rust.debug-assertions := True
configure: rust.overflow-checks := True
configure: llvm.assertions      := True
configure: dist.missing-tools   := True
configure: build.configure-args := ['--enable-sccache', '--disable-manage-submodu ...
configure: writing `config.toml` in current directory
configure: 
configure: run `python /checkout/x.py --help`
Attempting with retry: make prepare
---
tidy: Skipping binary file check, read-only filesystem
Checking which error codes lack tests...
* 632 error codes
* highest error code: E0790
tidy error: /checkout/compiler/rustc_builtin_macros/src/errors.rs:100: TODO is deprecated; use FIXME
Found 0 error(s) in error codes
Done!
* 380 features
some tidy checks failed

[davidtwco]

r? @davidtwco

[wonchulee]

FYI, this work continued at #101935

[davidtwco]

Closing in favour of #101935 then.