extract preresolve_literals_and_build_universe

Summary:
Small refactoring for the implementation of `buck2 build --target-universe` in the following diff D40254000.

The idea is that `buck2 build --target-universe` should resolve universe literals exactly how `buck2 cquery --target-universe` is implemented, so this code should be reused even if it is relatively simple.

Reviewed By: scottcao

Differential Revision: D40254558

fbshipit-source-id: 4e4b4d456d863c5ac5c3e1d61f90bd2d0cc59bea

buck2_build_api/src/query/cquery/evaluator.rs

@@ -48,13 +48,8 @@ impl CqueryEvaluator<'_> {
         eval_query(&self.functions, query, query_args, async move |literals| {
             let (universe, resolved_literals) = match target_universe {
                 None => {
-                    let resolved_literals = PreresolvedQueryLiterals::pre_resolve(
-                        &*self.dice_query_delegate,
-                        &literals,
-                    )
-                    .await;
-                    let universe = CqueryUniverse::build(&resolved_literals.literals()?).await?;
-                    (universe, resolved_literals)
+                    preresolve_literals_and_build_universe(&self.dice_query_delegate, &literals)
+                        .await?
                 }
                 Some(universe) => {
                     resolve_literals_in_universe(&self.dice_query_delegate, &literals, universe)
@@ -72,6 +67,19 @@ impl CqueryEvaluator<'_> {
     }
 }
 
+async fn preresolve_literals_and_build_universe(
+    dice_query_delegate: &DiceQueryDelegate<'_>,
+    literals: &[String],
+) -> anyhow::Result<(
+    CqueryUniverse,
+    PreresolvedQueryLiterals<ConfiguredTargetNode>,
+)> {
+    let resolved_literals =
+        PreresolvedQueryLiterals::pre_resolve(dice_query_delegate, literals).await;
+    let universe = CqueryUniverse::build(&resolved_literals.literals()?).await?;
+    Ok((universe, resolved_literals))
+}
+
 /// Evaluates some query expression. TargetNodes are resolved via the interpreter from
 /// the provided DiceCtx.
 pub async fn get_cquery_evaluator<'a, 'c: 'a>(