RuntimeIdentifiers doesn't set PlatformTarget

[davidmatson]

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net452</TargetFramework>
    <RuntimeIdentifiers>win-x64</RuntimeIdentifiers>
    <AssemblyName>Testx64</AssemblyName>
  </PropertyGroup>
</Project>

Expected:
64-bit assembly

Actual:
AnyCPU assembly

Current workaround is to add:

<PlatformTarget>x64</PlatformTarget>

[davkean]

This issue was moved to dotnet/sdk#1017