Ensure that Pack behaves correctly when a RID is set by the user.

Closes #55.

Author: alexrp

src/sdk/build/Vezel.Zig.Sdk.Overrides.targets

@@ -19,9 +19,12 @@
     <!--
     If a RuntimeIdentifier value has not been set, it means the Build, Clean,
     and Publish targets should run inner builds for every RID supported by the
-    project. That said, for running and testing, we still need to run natively
-    by default, so we still have to set a default RID. We use IsOuterBuild to
-    indicate whether inner builds are required.
+    project, and Pack should include artifacts from every RID. That said, for
+    running and testing, we still need to run natively by default, so we still
+    have to actually set a default RID.
+
+    We use IsOuterBuild to disambiguate between us setting a default RID and the
+    user setting a RID on their own.
     -->
     <PropertyGroup Condition="'$(RuntimeIdentifier)' == ''">
         <RuntimeIdentifier>$(NETCoreSdkPortableRuntimeIdentifier)</RuntimeIdentifier>

src/sdk/build/Vezel.Zig.Sdk.Pack.targets

@@ -24,8 +24,8 @@
 
         <!--
         Zig projects need to package all source code. C and C++ projects only
-        need to package public header files. We allow packaging headers with
-        Zig projects, but not Zig sources with C/C++ projects.
+        need to package public header files. We allow packaging headers with Zig
+        projects, but not Zig sources with C/C++ projects.
         -->
         <ItemGroup>
             <None Include="$(PublicHeadersPath)**/*.h; $(PublicHeadersPath)**/*.hxx"
@@ -41,7 +41,10 @@
         </ItemGroup>
 
         <ItemGroup>
-            <_RuntimeIdentifiers Include="$(RuntimeIdentifiers)" />
+            <_RuntimeIdentifiers Include="$(RuntimeIdentifier)"
+                                 Condition="'$(IsOuterBuild)' != 'true'" />
+            <_RuntimeIdentifiers Include="$(RuntimeIdentifiers)"
+                                 Condition="'$(IsOuterBuild)' == 'true'" />
         </ItemGroup>
 
         <MSBuild Projects="$(MSBuildProjectFullPath)"