Create a new product type so the PIF remains platform agnostic

Closes #610

Author: daveinglis

Sources/SWBApplePlatform/Specs/DarwinProductTypes.xcspec

@@ -474,4 +474,15 @@
             com.apple.package-type.mach-o-executable
         );
     },
+    {
+        _Domain = darwin;
+        Type = ProductType;
+        Identifier = org.swift.product-type.common.object;
+        BasedOn = com.apple.product-type.objfile;
+        Class = XCStandaloneExecutableProductType;
+        Description = "Object File";
+        IconNamePrefix = "TargetPlugin";
+        DefaultTargetName = "Object File";
+    },
+
 )

Sources/SWBGenericUnixPlatform/Specs/Unix.xcspec

@@ -80,4 +80,15 @@
         Identifier = com.apple.product-type.framework.static;
         BasedOn = com.apple.product-type.framework;
     },
+
+    {
+        Domain = generic-unix;
+        Type = ProductType;
+        Identifier = org.swift.product-type.common.object;
+        BasedOn = com.apple.product-type.objfile;
+        Class = XCStandaloneExecutableProductType;
+        Description = "Object File";
+        IconNamePrefix = "TargetPlugin";
+        DefaultTargetName = "Object File";
+    },
 )

Sources/SWBWindowsPlatform/Specs/Windows.xcspec

@@ -105,4 +105,15 @@
             },
         );
     },
+    {
+        Domain = windows;
+        Type = ProductType;
+        Identifier = org.swift.product-type.common.object;
+        BasedOn = org.swift.product-type.library.object;
+        Class = XCStandaloneExecutableProductType;
+        Name = "Object Library";
+        Description = "Object library";
+        IconNamePrefix = "TargetLibrary";
+        DefaultTargetName = "Object Library";
+    },
 )

Sources/SwiftBuild/ProjectModel/Targets.swift

@@ -310,6 +310,7 @@ extension ProjectModel {
         public enum ProductType: String, Sendable, Codable, CaseIterable {
             case application = "com.apple.product-type.application"
             case staticArchive = "com.apple.product-type.library.static"
+            case commonObject = "org.swift.product-type.common.object"
             case objectFile = "com.apple.product-type.objfile"
             case dynamicLibrary = "com.apple.product-type.library.dynamic"
             case framework = "com.apple.product-type.framework"