Do not emit CS1607 warnings for test builds

Author: AArnott

src/NerdBank.GitVersioning.Tests/BuildIntegrationTests.cs

@@ -1058,6 +1058,8 @@ private void MakeItAVBProject()
     {
         var csharpImport = this.testProject.Imports.Single(i => i.Project.Contains("CSharp"));
         csharpImport.Project = @"$(MSBuildToolsPath)\Microsoft.VisualBasic.targets";
+        var isVbProperty = this.testProject.Properties.Single(p => p.Name == "IsVB");
+        isVbProperty.Value = "true";
     }
 
     private struct RestoreEnvironmentVariables : IDisposable

src/NerdBank.GitVersioning.Tests/test.prj

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
+    <IsVB>false</IsVB>
     <RootNamespace>TestNamespace</RootNamespace>
     <AssemblyName>TestAssembly</AssemblyName>
     <AssemblyTitle>TestAssembly</AssemblyTitle>
@@ -11,6 +12,8 @@
     <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <OutputType>Library</OutputType>
     <OutputPath>bin\</OutputPath>
+    <NoWarn Condition=" '$(IsVB)' == 'false' ">$(NoWarn);1607</NoWarn>
+    <NoWarn Condition=" '$(IsVB)' == 'true' ">$(NoWarn);40010</NoWarn>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />