Fix recursive pattern queries skipping valid directories

Summary:
For recursive patterns with Unknown status, we were checking if a BUCK file
exists at the prefix path. This incorrectly filtered out valid recursive
queries like `fbcode//security/mfgsec/log_collector/...` where the prefix
directory exists but has no BUCK file directly.

Now we check:
- PatternType::Package -> does_package_exist (BUCK file check)
- PatternType::Recursive -> does_directory_exist (directory check)

Reviewed By: RiskRunner0

Differential Revision: D91609376

fbshipit-source-id: 7f31840d62ad610bfe15d53063a2d6286bf2589c

Author: Aaron Ho

td_util/src/buck/run.rs

@@ -21,6 +21,7 @@ use thiserror::Error;
 use tracing::info;
 
 use crate::cells::CellInfo;
+use crate::types::CellPath;
 use crate::types::Package;
 use crate::types::ProjectRelativePath;
 use crate::types::TargetPattern;
@@ -134,6 +135,14 @@ impl Buck2 {
         Ok(false)
     }
 
+    /// Does a directory exist for recursive queries. Doesn't actually invoke Buck2, but does look at the file system.
+    pub fn does_directory_exist(&mut self, cells: &CellInfo, x: &Package) -> anyhow::Result<bool> {
+        let root = self.root()?;
+        let cell_path = CellPath::new(x.as_str());
+        let resolved = cells.resolve(&cell_path)?;
+        Ok(root.join(resolved.as_str()).is_dir())
+    }
+
     pub fn targets(
         &mut self,
         extra_args: &[String],