async-await: add current_thread::Runtime::block_on_async (#1072)

This function is used by the Tokio macros introduced by #1058  but was
omitted from the PR.

ci/azure-cargo-check.yml

@@ -27,7 +27,3 @@ jobs:
       - script: cargo check ${{ parameters.noDefaultFeatures }} --features ${{ feature }}
         displayName: Check `${{ crate.key }}`, features = ${{ feature }}
         workingDirectory: $(Build.SourcesDirectory)/${{ crate.key }}
-
-  - ${{ if parameters.benches }}:
-    - script: cargo check --benches --all
-      displayName: Check benchmarks

ci/azure-test-nightly.yml

@@ -0,0 +1,23 @@
+jobs:
+- job: ${{ parameters.name }}
+  displayName: ${{ parameters.displayName }}
+  pool:
+    vmImage: ubuntu-16.04
+
+  steps:
+  - template: azure-install-rust.yml
+    parameters:
+      rust_version: ${{ parameters.rust }}
+
+  - template: azure-patch-crates.yml
+
+  - script: cargo test
+    displayName: cargo +nightly test -p async-await
+    workingDirectory: $(Build.SourcesDirectory)/async-await
+
+  - script: cargo check --all
+    displayName: cargo +nightly check --all
+
+  # Check benches
+  - script: cargo check --benches --all
+    displayName: Check benchmarks