Add React-Core-prebuild.podspec to integrate React native core prebuilds using cocoapods (#52133)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52133

Add React-Core-prebuild.podspec to integrate React native core prebuilds using cocoapods

## Context
This PR introduces the first working version of building React Native apps on iOS using prebuilt RNCore and cocoapods.

- Added React-Core-prebuilt.podspec for installing/consuming XCFrameworks
- Added logic in react_native_pods.rb for switching between build from source and using prebuilts
- Added rncore.rb - utilities for the ReactCore prebuilts
- Updated rndependencies with some extra error handling modelled after rncode.rb
- Added support for hard linking headers and modules in each inner framework in the XCFramework in xcframework.js

## Swift:
To enable support for the objective-c types from swift, the swift compiler uses a module map to gather exports from the framework (module.modulemap). This file basically points to an umbrella header file that exports the valid objective-c types (non c++) to Swift. In addition these files are read from the DerivedData and not the project source - so it is a bit hard to control everyting.

I was initially not able to use cocoapods own module definitions (module_name, module_file props) to use a custom module map. I finally found that these files are expected in the deriveddata (build folder) where only the active inner framework is copied - so then I had to hard link both module map and header files for each arch.

## Changelog:

[IOS] [ADDED] - Add `React-Core-prebuild.podspec` to integrate React native core prebuilds using cocoapods

Pull Request resolved: https://github.com/facebook/react-native/pull/52109

Test Plan:
Run with RN Tester. We need to remove all extra pods from RNTester pod file since none of them are yet compatible with prebuilt (they reference non-prebuilt pods)

Rollback Plan:

Reviewed By: cortinico

Differential Revision: D76980281

Pulled By: cipolleschi

fbshipit-source-id: ce102837d6df6ab0fa2e55862cc0c954125bd362

packages/react-native/React-Core-prebuilt.podspec

@@ -0,0 +1,109 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+require "json"
+
+package = JSON.parse(File.read(File.join(__dir__, "package.json")))
+version = package['version']
+
+source = ReactNativeCoreUtils.resolve_podspec_source()
+
+header_search_paths = [
+  "${PODS_ROOT}/Headers/Private/React-Core-prebuilt",
+  "${PODS_ROOT}/Headers/Private/React-Core-prebuilt/RCTDeprecation",
+  "${PODS_ROOT}/Headers/Private/React-Core-prebuilt/ReactCommon/yoga",
+  "${PODS_ROOT}/Headers/Private/React-Core-prebuilt/ReactCommon",
+  "${PODS_ROOT}/Headers/Private/React-Core-prebuilt/Libraries/AppDelegate",
+  "${PODS_ROOT}/Headers/Private/React-Core-prebuilt/Libraries",
+
+  "$(REACT_NATIVE_PATH)/React/Base",
+  "$(REACT_NATIVE_PATH)/ReactCommon",
+  "$(REACT_NATIVE_PATH)/Libraries",
+  "$(REACT_NATIVE_PATH)/ReactApple",
+  "$(REACT_NATIVE_PATH)/ReactCxxPlatform",
+  "$(REACT_NATIVE_PATH)/ReactCommon/react/runtime/platform/ios",
+  "${REACT_NATIVE_PATH}/ReactCommon/jsi",
+  "$(REACT_NATIVE_PATH)/ReactCommon/jsiexecutor/",
+  "$(REACT_NATIVE_PATH)/ReactCommon/react/nativemodule/samples/platform/ios",
+  "$(REACT_NATIVE_PATH)/ReactCommon/react/nativemodule/samples",
+]
+
+Pod::Spec.new do |spec|
+  spec.name                 = 'React-Core-prebuilt'
+  spec.version              = version
+  spec.summary              = "Prebuilt core of React Native."
+  spec.homepage             = "https://reactnative.dev/"
+  spec.description          = 'Prebuilt React Native Core libraries and headers'
+  spec.homepage             = 'https://github.com/facebook/react-native'
+  spec.license              = package['license']
+  spec.authors              = 'meta'
+  spec.platforms            = min_supported_versions
+  spec.source               = source
+
+  spec.vendored_frameworks  = "React.xcframework"
+
+  spec.preserve_paths       = '**/*.*'
+  spec.header_mappings_dir  = 'React.xcframework/Headers'
+  spec.source_files         = 'React.xcframework/Headers/**/*.{h,hpp}'
+
+  spec.module_name          = 'React'
+  spec.module_map           = 'React.xcframework/Modules/module.modulemap'
+  spec.public_header_files  = 'React.xcframework/Headers/**/*.h'
+
+  # Setup the consuming project's search paths
+  spec.user_target_xcconfig = {
+    "HEADER_SEARCH_PATHS" => header_search_paths,
+    "SWIFT_INCLUDE_PATHS" => "${PODS_ROOT}/Headers/Private/React-Core-prebuilt",
+    'DEFINES_MODULE' => 'YES',
+    'CLANG_ENABLE_MODULES' => 'YES',
+  }
+
+  spec.pod_target_xcconfig  = {
+    'WARNING_CFLAGS' => '-Wno-comma -Wno-shorten-64-to-32',
+    "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
+    'DEFINES_MODULE' => 'YES',
+    'CLANG_ENABLE_MODULES' => 'YES',
+  }
+
+  # We need to make sure that the React.xcframework is copied correctly - in the downloaded tarball
+  # the root directory is the framework, but when using it we need to have it in a subdirectory
+  # called React.xcframework, so we need to move the contents of the tarball into that directory.
+  # This is done in the prepare_command.
+  spec.prepare_command = <<~'CMD'
+    CURRENT_PATH=$(pwd)
+    XCFRAMEWORK_PATH="${CURRENT_PATH}/React.xcframework"
+    mkdir -p "${XCFRAMEWORK_PATH}"
+    find "$CURRENT_PATH" -mindepth 1 -maxdepth 1 ! -name "$(basename "$XCFRAMEWORK_PATH")" -exec mv {} "$XCFRAMEWORK_PATH" \;
+  CMD
+
+  # If we are passing a local tarball, we don't want to switch between Debug and Release
+  if !ENV["RCT_TESTONLY_RNCORE_TARBALL_PATH"]
+    script_phase = {
+      :name => "[RNDeps] Replace React Native Core for the right configuration, if needed",
+      :execution_position => :before_compile,
+      :script => <<-EOS
+      . "$REACT_NATIVE_PATH/scripts/xcode/with-environment.sh"
+
+      CONFIG="Release"
+      if echo $GCC_PREPROCESSOR_DEFINITIONS | grep -q "DEBUG=1"; then
+        CONFIG="Debug"
+      fi
+
+      # TODO(T228219721): Add this for React Native Core as well
+      ##### "$NODE_BINARY" "$REACT_NATIVE_PATH/third-party-podspecs/replace_dependencies_version.js" -c "$CONFIG" -r "#{version}" -p "$PODS_ROOT"
+      EOS
+    }
+
+
+    # :always_out_of_date is only available in CocoaPods 1.13.0 and later
+    if Gem::Version.new(Pod::VERSION) >= Gem::Version.new('1.13.0')
+      # always run the script without warning
+      script_phase[:always_out_of_date] = "1"
+    end
+
+    spec.script_phase = script_phase
+  end
+
+end