Hash Ident spans in all HIR structures

This PR removes all of the `#[stable_hasher(project(name))]`
attributes used in HIR structs. While these attributes are not known
to be causing any issues in practice, we need to hash these in
order for the incremental system to work correctly -
a query could be otherwise be incorrectly marked green
when a change occures in one of the `Span`s that it uses.

compiler/rustc_hir/src/hir.rs

@@ -205,7 +205,6 @@ impl Path<'_> {
 #[derive(Debug, HashStable_Generic)]
 pub struct PathSegment<'hir> {
     /// The identifier portion of this path segment.
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     // `id` and `res` are optional. We currently only use these in save-analysis,
     // any path segments without these will not have save-analysis info and
@@ -850,7 +849,6 @@ pub struct PatField<'hir> {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
     /// The identifier for the field.
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     /// The pattern the field is destructured to.
     pub pat: &'hir Pat<'hir>,
@@ -2113,7 +2111,6 @@ pub const FN_OUTPUT_NAME: Symbol = sym::Output;
 #[derive(Debug, HashStable_Generic)]
 pub struct TypeBinding<'hir> {
     pub hir_id: HirId,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub gen_args: &'hir GenericArgs<'hir>,
     pub kind: TypeBindingKind<'hir>,
@@ -2501,7 +2498,6 @@ pub struct EnumDef<'hir> {
 #[derive(Debug, HashStable_Generic)]
 pub struct Variant<'hir> {
     /// Name of the variant.
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     /// Id of the variant (not the constructor, see `VariantData::ctor_hir_id()`).
     pub id: HirId,
@@ -2591,7 +2587,6 @@ impl VisibilityKind<'_> {
 #[derive(Debug, HashStable_Generic)]
 pub struct FieldDef<'hir> {
     pub span: Span,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub vis: Visibility<'hir>,
     pub hir_id: HirId,
@@ -2850,7 +2845,6 @@ impl ItemKind<'_> {
 #[derive(Encodable, Debug, HashStable_Generic)]
 pub struct TraitItemRef {
     pub id: TraitItemId,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub kind: AssocItemKind,
     pub span: Span,
@@ -2866,7 +2860,6 @@ pub struct TraitItemRef {
 #[derive(Debug, HashStable_Generic)]
 pub struct ImplItemRef {
     pub id: ImplItemId,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub kind: AssocItemKind,
     pub span: Span,
@@ -2905,7 +2898,6 @@ impl ForeignItemId {
 #[derive(Debug, HashStable_Generic)]
 pub struct ForeignItemRef {
     pub id: ForeignItemId,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub span: Span,
 }

src/test/incremental/hashes/trait_defs.rs

@@ -400,7 +400,7 @@ trait TraitAddUnsafeModifier {
 #[cfg(not(any(cfail1,cfail4)))]
 #[rustc_clean(cfg="cfail2")]
 #[rustc_clean(cfg="cfail3")]
-#[rustc_clean(cfg="cfail5")]
+#[rustc_clean(except="hir_owner", cfg="cfail5")]
 #[rustc_clean(cfg="cfail6")]
 trait TraitAddUnsafeModifier {
     #[rustc_clean(except="hir_owner,fn_sig", cfg="cfail2")]
@@ -425,7 +425,7 @@ trait TraitAddExternModifier {
 #[cfg(not(any(cfail1,cfail4)))]
 #[rustc_clean(cfg="cfail2")]
 #[rustc_clean(cfg="cfail3")]
-#[rustc_clean(cfg="cfail5")]
+#[rustc_clean(except="hir_owner", cfg="cfail5")]
 #[rustc_clean(cfg="cfail6")]
 trait TraitAddExternModifier {
     #[rustc_clean(except="hir_owner,fn_sig", cfg="cfail2")]