The open source build has CompilerPackage project and CompilerPackageFiles...

The open source build has CompilerPackage project and CompilerPackageFiles project both of which generate CompilerPackage.dll.  This check in fixes that by renaming CompilerPackages dll to CompilerPackageVSIX.dll

Make a similar change to:
    VSWindowsDiagnostice, CSharpRepl and VBRepl (changeset 1210613)

Src/Compilers/Package/CompilerPackage.csproj

@@ -13,7 +13,7 @@
     <ProjectTypeGuids>{82b43b9b-a64c-4715-b499-d71e9ca2bd60};{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <OutputType>Library</OutputType>
     <RootNamespace>Microsoft.CompilerPackage</RootNamespace>
-    <AssemblyName>CompilerPackage</AssemblyName>
+    <AssemblyName>CompilerPackage.DoNotUse</AssemblyName>
     <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <PlatformTarget>x86</PlatformTarget>
     <StartAction>Program</StartAction>
@@ -26,6 +26,7 @@
     <StyleCopEnabled>false</StyleCopEnabled>
     <GeneratePkgDefFile>False</GeneratePkgDefFile>
     <IncludeAssemblyInVSIXContainer>false</IncludeAssemblyInVSIXContainer>
+    <TargetVsixContainerName>CompilerPackage.vsix</TargetVsixContainerName>
     <SolutionDir Condition="'$(SolutionDir)' == '' OR '$(SolutionDir)' == '*Undefined*'">..\..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
     <OutDir>..\..\..\Binaries\$(Configuration)\</OutDir>