Remove use of deprecated method

Author: sharwell

AsyncUsageAnalyzers/AsyncUsageAnalyzers.Test/Helpers/DiagnosticVerifier.Helper.cs

@@ -17,11 +17,11 @@ namespace TestHelper
     /// </summary>
     public abstract partial class DiagnosticVerifier
     {
-        private static readonly MetadataReference CorlibReference = MetadataReference.CreateFromAssembly(typeof(object).Assembly).WithAliases(ImmutableArray.Create("global", "corlib"));
-        private static readonly MetadataReference SystemReference = MetadataReference.CreateFromAssembly(typeof(System.Diagnostics.Debug).Assembly).WithAliases(ImmutableArray.Create("global", "system"));
-        private static readonly MetadataReference SystemCoreReference = MetadataReference.CreateFromAssembly(typeof(Enumerable).Assembly);
-        private static readonly MetadataReference CSharpSymbolsReference = MetadataReference.CreateFromAssembly(typeof(CSharpCompilation).Assembly);
-        private static readonly MetadataReference CodeAnalysisReference = MetadataReference.CreateFromAssembly(typeof(Compilation).Assembly);
+        private static readonly MetadataReference CorlibReference = MetadataReference.CreateFromFile(typeof(object).Assembly.Location).WithAliases(ImmutableArray.Create("global", "corlib"));
+        private static readonly MetadataReference SystemReference = MetadataReference.CreateFromFile(typeof(System.Diagnostics.Debug).Assembly.Location).WithAliases(ImmutableArray.Create("global", "system"));
+        private static readonly MetadataReference SystemCoreReference = MetadataReference.CreateFromFile(typeof(Enumerable).Assembly.Location);
+        private static readonly MetadataReference CSharpSymbolsReference = MetadataReference.CreateFromFile(typeof(CSharpCompilation).Assembly.Location);
+        private static readonly MetadataReference CodeAnalysisReference = MetadataReference.CreateFromFile(typeof(Compilation).Assembly.Location);
 
         private static readonly string DefaultFilePathPrefix = "Test";
         private static readonly string CSharpDefaultFileExt = "cs";