Stop ignoring Span field when hashing some Idents

This causes us to miss legitimate evaluatiosn (e.g. an upstream
`ExpnId` no longer exists), leading to ICEs when decoding stale
values from the incremental cache.

Author: Aaron1011

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,
 }

compiler/rustc_middle/src/ty/assoc.rs

@@ -43,7 +43,6 @@ impl AssocItemContainer {
 #[derive(Copy, Clone, Debug, PartialEq, HashStable, Eq, Hash)]
 pub struct AssocItem {
     pub def_id: DefId,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub kind: AssocKind,
     pub vis: Visibility,

compiler/rustc_middle/src/ty/mod.rs

@@ -1502,7 +1502,6 @@ pub struct VariantDef {
     /// If this variant is a struct variant, then this is `None`.
     pub ctor_def_id: Option<DefId>,
     /// Variant or struct name.
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     /// Discriminant of this variant.
     pub discr: VariantDiscr,
@@ -1598,7 +1597,6 @@ pub enum VariantDiscr {
 #[derive(Debug, HashStable, TyEncodable, TyDecodable)]
 pub struct FieldDef {
     pub did: DefId,
-    #[stable_hasher(project(name))]
     pub ident: Ident,
     pub vis: Visibility,
 }

src/test/incremental/issue-92192-expnid-hash/auxiliary/upstream.rs

@@ -0,0 +1,12 @@
+macro_rules! make_struct {
+    () => {
+        pub struct Foo;
+    }
+}
+
+
+#[cfg(rpass1)]
+make_struct!();
+
+#[cfg(rpass2)]
+make_struct!();

src/test/incremental/issue-92192-expnid-hash/main.rs

@@ -0,0 +1,14 @@
+// aux-build:upstream.rs
+// revisions: rpass1 rpass2
+
+extern crate upstream;
+
+struct Wrapper;
+
+impl Wrapper {
+    fn bar() {
+        let val: upstream::Foo;
+    }
+}
+
+fn main() {}