Rollup merge of #129829 - compiler-errors:decode-non-optional, r=lcnr

Make decoding non-optional `LazyArray` panic if not set

Tables may be [defined](https://github.com/rust-lang/rust/blob/9649706eada1b2c68cf6504356efb058f68ad739/compiler/rustc_metadata/src/rmeta/mod.rs#L377) as `optional:` or `defaulted:`. If optional, if we try to read a value from a key that was never encoded, we should panic. This has high value in ensuring correctness over a defaulted table, so the tradeoff is worth considering, since it signals the compiler has a buggy encode impl, rather than just defaulting to a value.

HOWEVER, `optional:` arrays were side-stepping this. So this PR fixes that, and makes `optional:` tables of `LazyArray` act like `LazyValue`, and panic if it's not assigned a value during encoding.

During this PR, I found that `deduced_param_attrs` has buggy (?? i think??) implementation where it will refuse to encode cross-crate `deduced_param_attrs` unless we're codegening, we're optimizing the library, and incremental is disabled. This seems incredibly wrong, but I don't want to fix it in this PR.
https://github.com/rust-lang/rust/blob/9649706eada1b2c68cf6504356efb058f68ad739/compiler/rustc_metadata/src/rmeta/encoder.rs#L1733-L1747

0 files changed, 0 insertions, 0 deletions