Auto merge of #116958 - oli-obk:coro, r=pnkfelix

rename Generator to Coroutine

implements rust-lang/compiler-team#682

While I did an automated replacement, I went through all changes manually to avoid renaming things like "id generators", "code generator", ...

I renamed files where that was necessary due to the contents referring to the crate name itself (mir opt, codegen or debuginfo tests), or required by tidy (feature gate docs)

* [x] rename various remaining abbreviated references to generators.
* [x] rename files
* [x] rename folders
* [x] add renamed feature: `generators`, ...

r? `@ghost`

Author: bors

compiler/rustc_abi/src/lib.rs

@@ -1502,7 +1502,7 @@ pub struct LayoutS<FieldIdx: Idx, VariantIdx: Idx> {
     /// Encodes information about multi-variant layouts.
     /// Even with `Multiple` variants, a layout still has its own fields! Those are then
     /// shared between all variants. One of them will be the discriminant,
-    /// but e.g. generators can have more.
+    /// but e.g. coroutines can have more.
     ///
     /// To access all fields of this layout, both `fields` and the fields of the active variant
     /// must be taken into account.

compiler/rustc_ast_lowering/messages.ftl

@@ -11,8 +11,8 @@ ast_lowering_argument = argument
 ast_lowering_assoc_ty_parentheses =
     parenthesized generic arguments cannot be used in associated type constraints
 
-ast_lowering_async_generators_not_supported =
-    `async` generators are not yet supported
+ast_lowering_async_coroutines_not_supported =
+    `async` coroutines are not yet supported
 
 ast_lowering_async_non_move_closure_not_supported =
     `async` non-`move` closures with parameters are not currently supported
@@ -42,6 +42,9 @@ ast_lowering_clobber_abi_not_supported =
 
 ast_lowering_closure_cannot_be_static = closures cannot be static
 
+ast_lowering_coroutine_too_many_parameters =
+    too many parameters for a coroutine (expected 0 or 1 parameters)
+
 ast_lowering_does_not_support_modifiers =
     the `{$class_name}` register class does not support template modifiers
 
@@ -53,9 +56,6 @@ ast_lowering_functional_record_update_destructuring_assignment =
     functional record updates are not allowed in destructuring assignments
     .suggestion = consider removing the trailing pattern
 
-ast_lowering_generator_too_many_parameters =
-    too many parameters for a generator (expected 0 or 1 parameters)
-
 ast_lowering_generic_type_with_parentheses =
     parenthesized type parameters may only be used with a `Fn` trait
     .label = only `Fn` traits may use parentheses