[tools] Fix computing the product version for Mac Catalyst. (#21868)

This fixes a problem with the version number in error messages when only Mac Catalyst is enabled in the build:

>  warning MT0079: The recommended Xcode version for Microsoft.MacCatalyst @IOS_NUGET_VERSION@ is Xcode 16.2 or later.

tools/common/Application.cs

@@ -1685,8 +1685,9 @@ internal ProductConstants ProductConstants {
 			get {
 				switch (Platform) {
 				case ApplePlatform.iOS:
-				case ApplePlatform.MacCatalyst:
 					return ProductConstants.iOS;
+				case ApplePlatform.MacCatalyst:
+					return ProductConstants.MacCatalyst;
 				case ApplePlatform.TVOS:
 					return ProductConstants.tvOS;
 				case ApplePlatform.MacOSX:

tools/common/Make.common

@@ -63,6 +63,7 @@ $(abspath ../common/ProductConstants.cs): ../common/ProductConstants.in.cs Makef
 		-e "s/@IOS_VERSION@/$(IOS_PACKAGE_VERSION_MAJOR).$(IOS_PACKAGE_VERSION_MINOR).$(IOS_PACKAGE_VERSION_REV)/g" \
 		-e "s/@TVOS_VERSION@/$(IOS_PACKAGE_VERSION_MAJOR).$(IOS_PACKAGE_VERSION_MINOR).$(IOS_PACKAGE_VERSION_REV)/g" \
 		-e "s/@MACOS_VERSION@/$(MAC_PACKAGE_VERSION_MAJOR).$(MAC_PACKAGE_VERSION_MINOR).$(MAC_PACKAGE_VERSION_REV)/g" \
+		-e "s/@MACCATALYST_VERSION@/$(IOS_PACKAGE_VERSION_MAJOR).$(IOS_PACKAGE_VERSION_MINOR).$(IOS_PACKAGE_VERSION_REV)/g" \
 		\
 		$(foreach platform,$(DOTNET_PLATFORMS_UPPERCASE),-e 's/@$(platform)_REVISION@/$($(platform)_COMMIT_DISTANCE) ($(CURRENT_BRANCH_SED_ESCAPED): $(CURRENT_HASH))/g')  \
 		$(foreach platform,$(DOTNET_PLATFORMS_UPPERCASE),-e 's/@$(platform)_NUGET_VERSION@/$($(platform)_NUGET_VERSION)/g')  \

tools/common/ProductConstants.in.cs

@@ -24,10 +24,12 @@ sealed class ProductConstants {
 		public readonly static ProductConstants iOS = new ProductConstants ("@IOS_NUGET_VERSION@", "@IOS_NUGET_REVISION@");
 		public readonly static ProductConstants tvOS = new ProductConstants ("@TVOS_NUGET_VERSION@", "@TVOS_NUGET_REVISION@");
 		public readonly static ProductConstants macOS = new ProductConstants ("@MACOS_NUGET_VERSION@", "@MACOS_NUGET_REVISION@");
+		public readonly static ProductConstants MacCatalyst = new ProductConstants ("@MACCATALYST_NUGET_VERSION@", "@MACCATALYST_NUGET_VERSION@");
 #else
 		public readonly static ProductConstants iOS = new ProductConstants ("@IOS_VERSION@", "@IOS_REVISION@");
 		public readonly static ProductConstants tvOS = new ProductConstants ("@TVOS_VERSION@", "@TVOS_REVISION@");
 		public readonly static ProductConstants macOS = new ProductConstants ("@MACOS_VERSION@", "@MACOS_REVISION@");
+		public readonly static ProductConstants MacCatalyst = new ProductConstants ("@MACCATALYST_VERSION@", "@MACCATALYST_REVISION@");
 #endif
 	}
 }