Auto merge of #103042 - davidtwco:translation-distributed-ftl, r=oli-obk

errors: generate typed identifiers in each crate

Instead of loading the Fluent resources for every crate in `rustc_error_messages`, each crate generates typed identifiers for its own diagnostics and creates a static which are pulled together in the `rustc_driver` crate and provided to the diagnostic emitter.

There are advantages and disadvantages to this change..

#### Advantages
- Changing a diagnostic now only recompiles the crate for that diagnostic and those crates that depend on it, rather than `rustc_error_messages` and all crates thereafter.
- This approach can be used to support first-party crates that want to supply translatable diagnostics (e.g. `rust-lang/thorin` in https://github.com/rust-lang/rust/pull/102612#discussion_r985372582, cc `@JhonnyBillM)`
- We can extend this a little so that tools built using rustc internals (like clippy or rustdoc) can add their own diagnostic resources (much more easily than those resources needing to be available to `rustc_error_messages`)

#### Disadvantages
- Crates can only refer to the diagnostic messages defined in the current crate (or those from dependencies), rather than all diagnostic messages.
- `rustc_driver` (or some other crate we create for this purpose) has to directly depend on *everything* that has error messages.
  - It already transitively depended on all these crates.

#### Pending work
- [x] I don't know how to make `rustc_codegen_gcc`'s translated diagnostics work with this approach - because `rustc_driver` can't depend on that crate and so can't get its resources to provide to the diagnostic emission. I don't really know how the alternative codegen backends are actually wired up to the compiler at all.
- [x] Update `triagebot.toml` to track the moved FTL files.

r? `@compiler-errors`
cc #100717

compiler/rustc_trait_selection/src/errors.rs

@@ -1,4 +1,5 @@
-use rustc_errors::{fluent, ErrorGuaranteed, Handler, IntoDiagnostic};
+use crate::fluent_generated as fluent;
+use rustc_errors::{ErrorGuaranteed, Handler, IntoDiagnostic};
 use rustc_macros::Diagnostic;
 use rustc_middle::ty::{self, PolyTraitRef, Ty};
 use rustc_span::{Span, Symbol};
@@ -69,19 +70,19 @@ impl IntoDiagnostic<'_> for NegativePositiveConflict<'_> {
         diag.code(rustc_errors::error_code!(E0751));
         match self.negative_impl_span {
             Ok(span) => {
-                diag.span_label(span, fluent::negative_implementation_here);
+                diag.span_label(span, fluent::trait_selection_negative_implementation_here);
             }
             Err(cname) => {
-                diag.note(fluent::negative_implementation_in_crate);
+                diag.note(fluent::trait_selection_negative_implementation_in_crate);
                 diag.set_arg("negative_impl_cname", cname.to_string());
             }
         }
         match self.positive_impl_span {
             Ok(span) => {
-                diag.span_label(span, fluent::positive_implementation_here);
+                diag.span_label(span, fluent::trait_selection_positive_implementation_here);
             }
             Err(cname) => {
-                diag.note(fluent::positive_implementation_in_crate);
+                diag.note(fluent::trait_selection_positive_implementation_in_crate);
                 diag.set_arg("positive_impl_cname", cname.to_string());
             }
         }

compiler/rustc_trait_selection/src/lib.rs

@@ -36,7 +36,12 @@ extern crate rustc_middle;
 #[macro_use]
 extern crate smallvec;
 
+use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
+use rustc_macros::fluent_messages;
+
 pub mod errors;
 pub mod infer;
 pub mod solve;
 pub mod traits;
+
+fluent_messages! { "../locales/en-US.ftl" }