Port #[path] to the new attribute parsing infrastructure

Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -298,6 +298,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_pass_by_value]` (used by the `rustc_pass_by_value` lint).
     PassByValue(Span),
 
+    /// Represents `#[path]`
+    Path(Symbol, Span),
+
     /// Represents `#[rustc_pub_transparent]` (used by the `repr_transparent_external_private_fields` lint).
     PubTransparent(Span),
 

compiler/rustc_attr_data_structures/src/encode_cross_crate.rs

@@ -40,6 +40,7 @@ impl AttributeKind {
             NonExhaustive(..) => Yes,
             Optimize(..) => No,
             PassByValue(..) => Yes,
+            Path(..) => No,
             PubTransparent(..) => Yes,
             Repr { .. } => No,
             RustcLayoutScalarValidRangeEnd(..) => Yes,