Add test for async function and async block

Author: mweber15

tests/codegen/issue-98678-async.rs

@@ -0,0 +1,25 @@
+// This test verifies the accuracy of emitted file and line debuginfo metadata for async blocks and
+// async functions.
+//
+// edition: 2021
+// compile-flags: -C debuginfo=2
+#![crate_type = "lib"]
+
+// ignore-tidy-linelength
+
+// NONMSVC-DAG: ![[#FILE:]] = !DIFile({{.*}}filename:{{.*}}/codegen/issue-98678-async.rs{{".*}})
+// MSVC: ![[#FILE:]] = !DIFile({{.*}}filename:{{.*}}\\codegen\\issue-98678-async.rs{{".*}})
+
+// NONMSVC-DAG: !DISubprogram(name: "foo",{{.*}}file: ![[#FILE]]{{.*}}line: [[# @LINE + 2]],
+// MSVC-DAG: !DISubprogram(name: "foo",{{.*}}file: ![[#FILE]]{{.*}}line: [[# @LINE + 1]],
+pub async fn foo() -> u8 { 5 }
+
+pub fn bar() -> impl std::future::Future<Output = u8> {
+    // NONMSVC: !DICompositeType({{.*"}}{async_block_env#0}{{".*}}file: ![[#FILE]]{{.*}}line: [[# @LINE + 2]],
+    // MSVC-DAG: !DICompositeType({{.*"}}enum2$<issue_98678_async::bar::async_block_env$0>{{".*}}file: ![[#FILE]]{{.*}}line: [[# @LINE + 1]],
+    async {
+        let x: u8 = foo().await;
+        x + 5
+    }
+
+}