Solution project passthrough doesn't support calling Build directly

### Steps to reproduce

With a simple solution

```
Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 15
VisualStudioVersion = 15.0.27130.2010
MinimumVisualStudioVersion = 15.0.26124.0
Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "proj1", "proj1\proj1.csproj", "{41A1218F-E59D-4AC9-9741-AC6356D0880B}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Release|Any CPU = Release|Any CPU
Release|x64 = Release|x64
Release|x86 = Release|x86
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
{41A1218F-E59D-4AC9-9741-AC6356D0880B}.Release|Any CPU.ActiveCfg = Release|Any CPU
{41A1218F-E59D-4AC9-9741-AC6356D0880B}.Release|Any CPU.Build.0 = Release|Any CPU
{41A1218F-E59D-4AC9-9741-AC6356D0880B}.Release|x64.ActiveCfg = Release|Any CPU
{41A1218F-E59D-4AC9-9741-AC6356D0880B}.Release|x64.Build.0 = Release|Any CPU
{41A1218F-E59D-4AC9-9741-AC6356D0880B}.Release|x86.ActiveCfg = Release|Any CPU
{41A1218F-E59D-4AC9-9741-AC6356D0880B}.Release|x86.Build.0 = Release|Any CPU
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
EndGlobalSection
GlobalSection(ExtensibilityGlobals) = postSolution
SolutionGuid = {4CDA96E1-5FDA-460E-811F-4C2D0BF46566}
EndGlobalSection
EndGlobal
```

Attempt to build the Build target of the project explicitly

```
msbuild simple_proj.sln /t:proj1:Build
```

### Expected behavior

Builds the Build target in `proj1.csproj`

### Actual behavior

```
C:\Users\raines\source\repos\simple_proj\simple_proj.sln.metaproj : error MSB4057: The target "proj1:Build" does not exist in the project. [C:\Users\raines\source\repos\simple_proj\simple_proj.sln]
```

### Environment data
MSBuild `15.5.180.51428`