Honor --unit-test-kind work with --unit-bench

Commit 512f20c ("Add unit-test-kind option to allow choosing bin or
lib") added support for specifying the unit test "kind" when running
unit tests.
The reasoning brought up there (and solution introduced) applies to unit
benches as well. So make --unit-bench honor the value of this option as
well.

Author: d-e-s-o

src/bin/cargo-flamegraph.rs

@@ -49,8 +49,8 @@ struct Opt {
     #[clap(long, group = "exec-args")]
     unit_test: Option<Option<String>>,
 
-    /// Kind of target (lib or bin) when running with <unit-test> which is may be
-    /// required when we have two targets with the same name.
+    /// Kind of target (lib or bin) when running with <unit-test> or <unit-bench> which is
+    /// may be required when we have two targets with the same name.
     #[clap(long)]
     unit_test_kind: Option<UnitTestTargetKind>,
 
@@ -469,8 +469,14 @@ fn main() -> anyhow::Result<()> {
         opt.package = Some(target.package);
         target.kind
     } else if let Some(unit_bench) = opt.unit_bench {
+        let kinds = match opt.unit_test_kind {
+            Some(UnitTestTargetKind::Bin) => &[TargetKind::Bin][..],
+            Some(UnitTestTargetKind::Lib) => &[TargetKind::Lib, TargetKind::RLib],
+            None => &[TargetKind::Bin, TargetKind::Lib, TargetKind::RLib],
+        };
+
         let target = find_unique_target(
-            &[TargetKind::Bin, TargetKind::Lib, TargetKind::RLib],
+            kinds,
             opt.package.as_deref(),
             opt.manifest_path.as_deref(),
             unit_bench.as_deref(),