[Build] Support public builds on the macOS 26 SDK

https://bugs.webkit.org/show_bug.cgi?id=294213
rdar://152747039

Reviewed by Abrar Rahman Protyasha.

Copy SDK additions from macOS Sequoia, and fix a couple build failures
in places where code is assuming an internal SDK.

Rename the directories containing SPI modules added in
https://commits.webkit.org/293940@main. Directory names need to match
the module name imported, so that the compiler enters the directory and
discovers the modulemap.

* Source/WebKit/Platform/cocoa/WKMaterialHostingSupport.swift:
* Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI_Private_SPI/WritingToolsUISPI.h: Renamed from Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI/WritingToolsUISPI.h.
* Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI_Private_SPI/module.modulemap: Renamed from Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI/module.modulemap.
* Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools_SPI/WritingToolsSPI.h: Renamed from Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools/WritingToolsSPI.h.
* Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools_SPI/module.modulemap: Renamed from Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools/module.modulemap.
* Source/WebKit/_WebKit_SwiftUI/Implementation/WebViewRepresentable.swift:
(WebPageWebView.configureScrollInputBehavior(_:for:)):
* WebKitLibraries/SDKs/macosx26.0-additions.sdk/SDKSettings.plist: Added.
* WebKitLibraries/SDKs/macosx26.0-additions.sdk/SymlinkedHeaders-output.xcfilelist: Added.
* WebKitLibraries/SDKs/macosx26.0-additions.sdk/SymlinkedHeaders.xcfilelist: Added.
* WebKitLibraries/SDKs/macosx26.0-additions.sdk/usr/local/include/AvailabilityProhibitedInternal.h: Added.

Canonical link: https://commits.webkit.org/296023@main

Author: emw-apple

Source/WebKit/Platform/cocoa/WKMaterialHostingSupport.swift

@@ -21,7 +21,7 @@
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 // THE POSSIBILITY OF SUCH DAMAGE.
 
-#if HAVE_MATERIAL_EFFECT
+#if HAVE_MATERIAL_HOSTING
 
 internal import WebKit_Internal
 

…dules/WritingToolsUI/WritingToolsUISPI.h …gToolsUI_Private_SPI/WritingToolsUISPI.hSource/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI/WritingToolsUISPI.h renamed to Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI_Private_SPI/WritingToolsUISPI.h Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI/WritingToolsUISPI.h renamed to Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI_Private_SPI/WritingToolsUISPI.h

@@ -24,6 +24,13 @@
 internal import SwiftUI
 @_spi(CrossImportOverlay) import WebKit
 
+#if !USE_APPLE_INTERNAL_SDK
+// Stubs for behavior not implemented in open source.
+extension WebPageWebView {
+    public func configureScrollInputBehavior(_ behavior: Any, for input: Any) { }
+}
+#endif
+
 @MainActor
 struct WebViewRepresentable {
     let page: WebPage

…/Modules/WritingToolsUI/module.modulemap …tingToolsUI_Private_SPI/module.modulemapSource/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI/module.modulemap renamed to Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI_Private_SPI/module.modulemap Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI/module.modulemap renamed to Source/WebKit/Platform/spi/Cocoa/Modules/WritingToolsUI_Private_SPI/module.modulemap

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CanonicalName</key>
+	<string>WebKitSDKAdditions_macosx</string>
+	<key>HeaderSearchPaths</key>
+	<array>
+		<string>usr/local/include</string>
+	</array>
+	<key>IsBaseSDK</key>
+	<string>NO</string>
+</dict>
+</plist>

…a/Modules/WritingTools/WritingToolsSPI.h …dules/WritingTools_SPI/WritingToolsSPI.hSource/WebKit/Platform/spi/Cocoa/Modules/WritingTools/WritingToolsSPI.h renamed to Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools_SPI/WritingToolsSPI.h Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools/WritingToolsSPI.h renamed to Source/WebKit/Platform/spi/Cocoa/Modules/WritingTools_SPI/WritingToolsSPI.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2023 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+// Handle __IOS_PROHIBITED and friends.
+#undef __OS_AVAILABILITY
+#define __OS_AVAILABILITY(...)
+
+#undef SWIFT_AVAILABILITY
+#define SWIFT_AVAILABILITY __NULL_AVAILABILITY
+
+// Take care of {A,S}PI_DEPRECATED{,WITH_REPLACEMENT}{,_BEGIN,_END}
+#undef __API_DEPRECATED_MSG_GET_MACRO
+#define __API_DEPRECATED_MSG_GET_MACRO(...) __NULL_AVAILABILITY
+
+// Take care of {A,S}PI_AVAILABLE{,_BEGIN,_END}
+#undef __API_AVAILABLE_GET_MACRO
+#define __API_AVAILABLE_GET_MACRO(...) __NULL_AVAILABILITY
+
+// Take care of API_UNAVAILABLE{,_BEGIN,_END}
+#undef __API_UNAVAILABLE_GET_MACRO
+#define __API_UNAVAILABLE_GET_MACRO(...) __NULL_AVAILABILITY
+
+// Starting in iOS 18.4 and aligned SDKs, AvailabilityInternal.h has a hash
+// number used to detect accidental use of multiple copies of the library. Keep
+// track of known hashes and undef the hashed macro names. When encountering an
+// unknown hash, emit an error to avoid confusing build failures.
+#define __WEBKIT_OVERRIDDEN_AVAILABILITY_VERSIONS_VERSION_HASH 93585900U
+#if defined(__AVAILABILITY_VERSIONS_VERSION_HASH) && (__AVAILABILITY_VERSIONS_VERSION_HASH != 93585900U)
+#error __AVAILABILITY_VERSIONS_VERSION_HASH not recognized, please add it to WebKit's AvailabilityProhibitedInternal.h to silence availability errors.
+#endif
+
+#ifdef __API_AVAILABLE_GET_MACRO_93585900
+#undef __API_AVAILABLE_GET_MACRO_93585900
+#define __API_AVAILABLE_GET_MACRO_93585900(...) __NULL_AVAILABILITY
+#undef __API_UNAVAILABLE_GET_MACRO_93585900
+#define __API_UNAVAILABLE_GET_MACRO_93585900(...) __NULL_AVAILABILITY
+#endif
+
+#define __NULL_AVAILABILITY(...)