types: add explicit conversions from owned paths types to unsized ref

Summary:
There are scenarios where an &PathComponentBuf or a &RepoPath will show up.
An example when using get from a HashMap. These are not the references that we
are looking for. We want &PathComponent and &RepoPath respectively. Adding
explicit conversions.

(Note: this ignores all push blocking failures!)

Reviewed By: quark-zju

Differential Revision: D14292711

fbshipit-source-id: 29f4de25c2ffebf7f009e4f2515e0ba8f0371ae0

lib/types/src/path.rs

@@ -89,6 +89,11 @@ impl RepoPathBuf {
         Ok(RepoPathBuf(s))
     }
 
+    /// Converts the `RepoPathBuf` in a `RepoPath`.
+    pub fn as_repo_path(&self) -> &RepoPath {
+        self
+    }
+
     /// Returns whether the current `RepoPathBuf` has no components. Since `RepoPathBuf`
     /// represents the relative path from the start of the repository this is equivalent to
     /// checking whether the path is the root of the repository
@@ -276,6 +281,11 @@ impl PathComponentBuf {
         Ok(PathComponentBuf(s))
     }
 
+    /// Converts the `PathComponentBuf` in a `PathComponent`.
+    pub fn as_path_component(&self) -> &PathComponent {
+        self
+    }
+
     fn from_string_unchecked(s: String) -> Self {
         PathComponentBuf(s)
     }