* [msbuild] Set $(CscDebugFileExt) also, whenever overriding $(CscToolExe)
- This property was introduced in mono's msbuild, but will be upstream
also
- This *must* be set before Microsoft.CSharp.targets file is imported.
- Even though the msbuild targets will automatically select `.mdb` if
the `$(CscToolExe)` is `mcs` or `mcs.exe`, it would be a good
practice to set both the properties together.
- This came up in cases where we use `smcs`, because in that case the
msbuild targets end up using `.pdb`.
* [msbuild] Set `$(CscDebugFileExt)` == `.mdb`
Xamarin.ObjcBinding.CSharp.targets: Set the debug file extension also,
since we are overriding the compiler via `$(CscToolExe)`. Also, move
the property definition around to ensure that they are set *before*
importing `Microsoft.CSharp.targets`.