Track if a where bound comes from a impl Trait desugar

With rust-lang#93803 `impl Trait` function arguments get desugared to hidden
where bounds. However, Clippy needs to know if a bound was originally a
impl Trait or an actual bound. This adds a field to the
`WhereBoundPredicate` struct to keep track of this information during
HIR lowering.

Author: flip1995

clippy_lints/src/lifetimes.rs

@@ -9,8 +9,8 @@ use rustc_hir::intravisit::{
 use rustc_hir::FnRetTy::Return;
 use rustc_hir::{
     BareFnTy, BodyId, FnDecl, GenericArg, GenericBound, GenericParam, GenericParamKind, Generics, Impl, ImplItem,
-    ImplItemKind, Item, ItemKind, LangItem, Lifetime, LifetimeName, ParamName, PolyTraitRef, TraitBoundModifier,
-    TraitFn, TraitItem, TraitItemKind, Ty, TyKind, WherePredicate,
+    ImplItemKind, Item, ItemKind, LangItem, Lifetime, LifetimeName, ParamName, PolyTraitRef, PredicateOrigin,
+    TraitBoundModifier, TraitFn, TraitItem, TraitItemKind, Ty, TyKind, WherePredicate,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter as middle_nested_filter;
@@ -145,7 +145,7 @@ fn check_fn_inner<'tcx>(
         .filter(|param| matches!(param.kind, GenericParamKind::Type { .. }));
     for typ in types {
         for pred in generics.bounds_for_param(cx.tcx.hir().local_def_id(typ.hir_id)) {
-            if pred.in_where_clause {
+            if pred.origin == PredicateOrigin::WhereClause {
                 // has_where_lifetimes checked that this predicate contains no lifetime.
                 continue;
             }

clippy_lints/src/trait_bounds.rs

@@ -8,7 +8,8 @@ use rustc_data_structures::unhash::UnhashMap;
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::{
-    GenericBound, Generics, Item, ItemKind, Node, Path, PathSegment, QPath, TraitItem, Ty, TyKind, WherePredicate,
+    GenericBound, Generics, Item, ItemKind, Node, Path, PathSegment, PredicateOrigin, QPath, TraitItem, Ty, TyKind,
+    WherePredicate,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
@@ -95,6 +96,7 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
         for predicate in item.generics.predicates {
             if_chain! {
                 if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate;
+                if bound_predicate.origin != PredicateOrigin::ImplTrait;
                 if !bound_predicate.span.from_expansion();
                 if let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind;
                 if let Some(PathSegment {
@@ -168,6 +170,7 @@ impl TraitBounds {
         for bound in gen.predicates {
             if_chain! {
                 if let WherePredicate::BoundPredicate(ref p) = bound;
+                if p.origin != PredicateOrigin::ImplTrait;
                 if p.bounds.len() as u64 <= self.max_trait_bounds;
                 if !p.span.from_expansion();
                 if let Some(ref v) = map.insert(
@@ -223,6 +226,7 @@ fn check_trait_bound_duplication(cx: &LateContext<'_>, gen: &'_ Generics<'_>) {
     for predicate in gen.predicates {
         if_chain! {
             if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate;
+            if bound_predicate.origin != PredicateOrigin::ImplTrait;
             if !bound_predicate.span.from_expansion();
             if let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind;
             if let Some(segment) = segments.first();