Auto merge of #91779 - ridwanabdillahi:natvis, r=michaelwoerister

Add a new Rust attribute to support embedding debugger visualizers

Implemented [this RFC](https://github.com/rust-lang/rfcs/pull/3191) to add support for embedding debugger visualizers into a PDB.

Added a new attribute `#[debugger_visualizer]` and updated the `CrateMetadata` to store debugger visualizers for crate dependencies.

RFC: https://github.com/rust-lang/rfcs/pull/3191

compiler/rustc_span/src/lib.rs

@@ -70,6 +70,7 @@ use std::hash::Hash;
 use std::ops::{Add, Range, Sub};
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
+use std::sync::Arc;
 
 use md5::Digest;
 use md5::Md5;
@@ -1199,6 +1200,28 @@ impl SourceFileHash {
     }
 }
 
+#[derive(HashStable_Generic)]
+#[derive(Copy, PartialEq, PartialOrd, Clone, Ord, Eq, Hash, Debug, Encodable, Decodable)]
+pub enum DebuggerVisualizerType {
+    Natvis,
+}
+
+/// A single debugger visualizer file.
+#[derive(HashStable_Generic)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord, Encodable, Decodable)]
+pub struct DebuggerVisualizerFile {
+    /// The complete debugger visualizer source.
+    pub src: Arc<[u8]>,
+    /// Indicates which visualizer type this targets.
+    pub visualizer_type: DebuggerVisualizerType,
+}
+
+impl DebuggerVisualizerFile {
+    pub fn new(src: Arc<[u8]>, visualizer_type: DebuggerVisualizerType) -> Self {
+        DebuggerVisualizerFile { src, visualizer_type }
+    }
+}
+
 /// A single source in the [`SourceMap`].
 #[derive(Clone)]
 pub struct SourceFile {