Update iOS Fabric-related files to compile on OSS (#29810)

Summary:
Original PR contents:

This pull request updates the Podspecs and associated build scripts, and some source files so they build on OSS. RNTester now compiles with `fabric_enabled` again.

The following changes have been made:

 * Various spots that were pointing to the old `ReactCommon/fabric` location have now been updated to `ReactCommon/react/renderer`
 * Files that were attempting to use internal FB header `FBRCTFabricComponentsPlugins.h` were changed to use `RCTFabricComponentsPlugins.h`
 * `RCTFabricComponentsPlugins` in OSS was updated to include the `Image` fabric component (thanks tsapeta)
 * Replaced old `generate-rncore.sh` build script with new `generate-rncore.js` script which does not require `flow-node` and uses the `react-native-codegen` API directly, so there is no longer any need for an interim `schema-rncore.json` file.
 * Updated Yoga podspec which wasn't fully synced with changes from the main Yoga repo
 * Updated Fabric podspec with additional needed subspecs

Additions to PR by hramos:
* Replaced use of generate-rncore scripts with the original generate-native-modules-specs.sh script, which is now generate-specs.sh and supports both codegen for Native Modules and Components now (TurboModules/Fabric).
* Codegen now runs at build time as part of the Xcode build pipeline instead of as part of `pod install`. The build script is injected by the FBReactNativeSpec pod, as the pod is part of both Fabric and non-Fabric builds.

[General] [Fixed] - RNTester compiles with `fabric_enabled` again

Pull Request resolved: https://github.com/facebook/react-native/pull/29810

Test Plan:
RNTester now compiles and runs in the simulator again when `fabric_enabled` is set to `true`.

```
cd xplat/js/react-native-github/packages/rn-tester
USE_FABRIC=1 pod install
open RNTesterPods.xcworkspace
```

Reviewed By: fkgozali

Differential Revision: D24058507

Pulled By: hramos

fbshipit-source-id: 8b2ea3694e6cb9aa23f83f087e2995fd4320e2bb

scripts/generate-rncore.sh

@@ -1,14 +0,0 @@
-#!/bin/bash
-# Copyright (c) Facebook, Inc. and its affiliates.
-#
-# This source code is licensed under the MIT license found in the
-# LICENSE file in the root directory of this source tree.
-
-# This script collects the "core" component schemas used by fabric
-# then uses react-native-codegen to generate the component headers
-# to a location that the podspecs expect.
-
-# shellcheck disable=SC2038
-
-find "$PWD/../Libraries" -name "*NativeComponent.js" -print | xargs yarn flow-node packages/react-native-codegen/src/cli/combine/combine-js-to-schema-cli.js schema-rncore.json
-yarn flow-node packages/react-native-codegen/buck_tests/generate-tests.js schema-rncore.json rncore ReactCommon/fabric/components/rncore rncore

scripts/generate-specs-cli.js

@@ -25,7 +25,7 @@ const path = require('path');
 
 const GENERATORS = {
   android: ['modulesAndroid'],
-  ios: ['modulesIOS'],
+  ios: ['componentsIOS', 'modulesIOS'],
 };
 
 function generateSpec(

scripts/generate-specs.sh

@@ -5,18 +5,18 @@
 # LICENSE file in the root directory of this source tree.
 
 # This script collects the JavaScript spec definitions for core
-# native modules, then uses react-native-codegen to generate
-# native code.
+# native modules and components, then uses react-native-codegen
+# to generate native code.
 # The script will use the local react-native-codegen package by
 # default. Optionally, set the CODEGEN_PATH to point to the
 # desired codegen library (e.g. when using react-native-codegen
 # from npm).
 #
 # Usage:
-#   ./scripts/generate-native-modules-specs.sh
+#   ./scripts/generate-specs.sh
 #
-# Example:
-#  CODEGEN_PATH=.. ./scripts/generate-native-modules-specs.sh
+# Examples:
+#  CODEGEN_PATH=.. ./scripts/generate-specs.sh
 
 # shellcheck disable=SC2038
 
@@ -27,6 +27,7 @@ TEMP_DIR=$(mktemp -d /tmp/react-native-codegen-XXXXXXXX)
 RN_DIR=$(cd "$THIS_DIR/.." && pwd)
 CODEGEN_PATH="${CODEGEN_PATH:-$(cd "$RN_DIR/packages/react-native-codegen" && pwd)}"
 YARN_BINARY="${YARN_BINARY:-$(command -v yarn)}"
+USE_FABRIC="${USE_FABRIC:-0}"
 
 cleanup () {
   set +e
@@ -38,12 +39,14 @@ describe () {
   printf "\\n\\n>>>>> %s\\n\\n\\n" "$1"
 }
 
-run_codegen () {
-  SRCS_DIR=$1
-  LIBRARY_NAME=$2
-  OUTPUT_DIR=$3
+main() {
+  SRCS_DIR=$(cd "$RN_DIR/Libraries" && pwd)
 
-  SCHEMA_FILE="$TEMP_DIR/schema-$LIBRARY_NAME.json"
+  OUTPUT_DIR="$TEMP_DIR/out"
+  COMPONENTS_DIR="$RN_DIR/ReactCommon/react/renderer/components/rncore"
+  MODULES_DIR="$RN_DIR/Libraries/FBReactNativeSpec/FBReactNativeSpec"
+
+  SCHEMA_FILE="$TEMP_DIR/schema.json"
 
   if [ ! -d "$CODEGEN_PATH/lib" ]; then
     describe "Building react-native-codegen package"
@@ -58,21 +61,13 @@ run_codegen () {
 
   describe "Generating native code from schema (iOS)"
   pushd "$RN_DIR" >/dev/null || exit
-    "$YARN_BINARY" --silent node scripts/generate-native-modules-specs-cli.js ios "$SCHEMA_FILE" "$OUTPUT_DIR"
+    USE_FABRIC="$USE_FABRIC" "$YARN_BINARY" --silent node scripts/generate-specs-cli.js ios "$SCHEMA_FILE" "$OUTPUT_DIR"
   popd >/dev/null || exit
-}
 
-# Handle Core Modules
-run_codegen_core_modules () {
-  LIBRARY_NAME="FBReactNativeSpec"
-  SRCS_DIR=$(cd "$RN_DIR/Libraries" && pwd)
-  OUTPUT_DIR="$SRCS_DIR/$LIBRARY_NAME/$LIBRARY_NAME"
-
-  run_codegen "$SRCS_DIR" "$LIBRARY_NAME" "$OUTPUT_DIR"
-}
-
-main() {
-  run_codegen_core_modules
+  mkdir -p "$COMPONENTS_DIR" "$MODULES_DIR"
+  mv "$OUTPUT_DIR/FBReactNativeSpec.h" "$OUTPUT_DIR/FBReactNativeSpec-generated.mm" "$MODULES_DIR"
+  find "$OUTPUT_DIR" -type f | xargs sed -i '' 's/FBReactNativeSpec/rncore/g'
+  cp -R "$OUTPUT_DIR/." "$COMPONENTS_DIR"
 }
 
 trap cleanup EXIT

scripts/react_native_pods.rb

@@ -55,7 +55,7 @@ def use_react_native! (options={})
 
   if fabric_enabled
     pod 'React-Fabric', :path => "#{prefix}/ReactCommon"
-    pod 'React-graphics', :path => "#{prefix}/ReactCommon/fabric/graphics"
+    pod 'React-graphics', :path => "#{prefix}/ReactCommon/react/renderer/graphics"
     pod 'React-jsi/Fabric', :path => "#{prefix}/ReactCommon/jsi"
     pod 'React-RCTFabric', :path => "#{prefix}/React"
     pod 'RCT-Folly/Fabric', :podspec => "#{prefix}/third-party-podspecs/RCT-Folly.podspec"