Update version of Microsoft.CodeAnalysis.CSharp in Roslyn benchmarks because newer BDN

Author: cincuranet

src/benchmarks/real-world/Roslyn/CompilerBenchmarks.csproj

@@ -15,7 +15,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.5.0" />
   </ItemGroup>
 
   <ItemGroup>