How does it work in Mono's C# compiler?

<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProductVersion>9.0.30729</ProductVersion>
    <SchemaVersion>2.0</SchemaVersion>
    <ProjectGuid>{D4A01C5B-A1B5-48F5-BB5B-D2E1BD236E56}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <AppDesignerFolder>Properties</AppDesignerFolder>
    <RootNamespace>gmcs</RootNamespace>
    <AssemblyName>gmcs</AssemblyName>
    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
    <FileAlignment>512</FileAlignment>
    <FileUpgradeFlags>
    </FileUpgradeFlags>
    <OldToolsVersion>3.5</OldToolsVersion>
    <UpgradeBackupLocation />
    <PublishUrl>publish\</PublishUrl>
    <Install>true</Install>
    <InstallFrom>Disk</InstallFrom>
    <UpdateEnabled>false</UpdateEnabled>
    <UpdateMode>Foreground</UpdateMode>
    <UpdateInterval>7</UpdateInterval>
    <UpdateIntervalUnits>Days</UpdateIntervalUnits>
    <UpdatePeriodically>false</UpdatePeriodically>
    <UpdateRequired>false</UpdateRequired>
    <MapFileExtensions>true</MapFileExtensions>
    <ApplicationRevision>0</ApplicationRevision>
    <ApplicationVersion>1.0.0.%2a</ApplicationVersion>
    <IsWebBootstrapper>false</IsWebBootstrapper>
    <UseApplicationTrust>false</UseApplicationTrust>
    <BootstrapperEnabled>true</BootstrapperEnabled>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>.\</OutputPath>
    <DefineConstants>DEBUG;TRACE;NET_2_0;MS_COMPATIBLE;GMCS_SOURCE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <UseVSHostingProcess>false</UseVSHostingProcess>
    <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <DefineConstants>TRACE;NET_2_0;MS_COMPATIBLE;GMCS_SOURCE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <DefineConstants>TRACE;NET_2_0;MS_COMPATIBLE;GMCS_SOURCE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <OutputPath>.\</OutputPath>
    <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Data" />
    <Reference Include="System.Xml" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="argument.cs" />
    <Compile Include="AssemblyInfo.cs">
    </Compile>
    <Compile Include="anonymous.cs">
    </Compile>
    <Compile Include="assign.cs">
    </Compile>
    <Compile Include="attribute.cs">
    </Compile>
    <Compile Include="cfold.cs">
    </Compile>
    <Compile Include="class.cs">
    </Compile>
    <Compile Include="codegen.cs">
    </Compile>
    <Compile Include="complete.cs" />
    <Compile Include="const.cs">
    </Compile>
    <Compile Include="constant.cs">
    </Compile>
    <Compile Include="context.cs" />
    <Compile Include="convert.cs">
    </Compile>
    <Compile Include="CryptoConvert.cs" />
    <Compile Include="dynamic.cs" />
    <Compile Include="eval.cs" />
    <Compile Include="lambda.cs">
    </Compile>
    <Compile Include="cs-parser.cs" />
    <Compile Include="cs-tokenizer.cs">
    </Compile>
    <Compile Include="decl.cs">
    </Compile>
    <Compile Include="delegate.cs">
    </Compile>
    <Compile Include="doc.cs">
    </Compile>
    <Compile Include="driver.cs">
    </Compile>
    <Compile Include="ecore.cs">
    </Compile>
    <Compile Include="enum.cs">
    </Compile>
    <Compile Include="expression.cs">
    </Compile>
    <Compile Include="flowanalysis.cs">
    </Compile>
    <Compile Include="generic.cs" />
    <Compile Include="iterators.cs">
    </Compile>
    <Compile Include="literal.cs">
    </Compile>
    <Compile Include="location.cs">
    </Compile>
    <Compile Include="modifiers.cs">
    </Compile>
    <Compile Include="MonoSymbolFile.cs" />
    <Compile Include="MonoSymbolTable.cs" />
    <Compile Include="MonoSymbolWriter.cs" />
    <Compile Include="namespace.cs">
    </Compile>
    <Compile Include="nullable.cs">
    </Compile>
    <Compile Include="outline.cs" />
    <Compile Include="parameter.cs">
    </Compile>
    <Compile Include="pending.cs">
    </Compile>
    <Compile Include="report.cs">
    </Compile>
    <Compile Include="rootcontext.cs">
    </Compile>
    <Compile Include="roottypes.cs">
    </Compile>
    <Compile Include="statement.cs">
    </Compile>
    <Compile Include="support.cs">
    </Compile>
    <Compile Include="symbolwriter.cs">
    </Compile>
    <Compile Include="typemanager.cs">
    </Compile>
    <Compile Include="linq.cs" />
  </ItemGroup>
  <ItemGroup>
    <Folder Include="Properties\" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Consts.cs" />
  </ItemGroup>
  <ItemGroup>
    <BootstrapperPackage Include="Microsoft.Net.Client.3.5">
      <Visible>False</Visible>
      <ProductName>.NET Framework 3.5 SP1 Client Profile</ProductName>
      <Install>false</Install>
    </BootstrapperPackage>
    <BootstrapperPackage Include="Microsoft.Net.Framework.3.5.SP1">
      <Visible>False</Visible>
      <ProductName>.NET Framework 3.5 SP1</ProductName>
      <Install>true</Install>
    </BootstrapperPackage>
    <BootstrapperPackage Include="Microsoft.Windows.Installer.3.1">
      <Visible>False</Visible>
      <ProductName>Windows Installer 3.1</ProductName>
      <Install>true</Install>
    </BootstrapperPackage>
  </ItemGroup>
  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
       Other similar extension points exist, see Microsoft.Common.targets.
  <Target Name="BeforeBuild">
  </Target>
  <Target Name="AfterBuild">
  </Target>
  -->
</Project>