Add Fasta tests.

pkg/fasta/test/casts.dart.dartk.expect

Index: pkg/fasta/test/casts.dart.dartk.expect
diff --git a/pkg/fasta/test/casts.dart.dartk.expect b/pkg/fasta/test/casts.dart.dartk.expect
new file mode 100644
index 0000000000000000000000000000000000000000..c75d8ec820bf98d784206c6bd6d0e9bc98d86c82
--- /dev/null
+++ b/pkg/fasta/test/casts.dart.dartk.expect
@@ -0,0 +1,18 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+static method main() → dynamic {
+  core::print("" as core::String);
+  core::print(1 as core::int);
+  core::print(1.0 as core::double);
+  core::print("" is core::String);
+  core::print("" is core::int);
+  core::print("" is core::double);
+  core::print(1 is core::String);
+  core::print(1 is core::int);
+  core::print(1 is core::double);
+  core::print(1.0 is core::String);
+  core::print(1.0 is core::int);
+  core::print(1.0 is core::double);
+}