When building the `inspector` project with msbuild, the build fails
because of a missing `System.Runtime` reference,
-> which can be traced to the `ResolveAssemblyReferences` task not resolving dependencies.
-> which can be traced to `$(_FindDependencies)` property being set to false
-> which is false, because `$(BuildingProject)` is false, which should
have been set by the `BuildOnlySettings` target, run as a dependency of
`CoreBuild`.
We override `$(BuildDependsOn)` as:
<BuildDependsOn>
...
_UnpackLibraryResources;
$(BuildDependsOn);
...
</BuildDependsOn>
.. so, `_UnpackLibraryResources` runs before `BuildOnlySettings`. And
`_UnpackLibraryResources` depends on `ResolveReferences`, so the
`ResolveAssemblyReferences` task runs with the incorrect properties. And
later, during the build when `ResolveAssemblyReferences` is invoked
again, it gets skipped and the incorrect outputs get used.
`$(BuildingProject)` should be true for a project build. So,
`Xamarin.Mac.Common.targets` are fixed for that. And other similar
target files are also fixed.
Note: `Xamarin.iOS.Common.targets` already does this correctly.
Note: `$(BuildingProject)` is not used in xbuild, so this bug is seen
only when building with msbuild.
4a87ccf948