Fix ios build error when podfile generate_multiple_pod_projects=true …

…and fabric is on (facebook#33381)

Summary:
there are build errors happened when in [`generate_multiple_pod_projects`](https://blog.cocoapods.org/CocoaPods-1.7.0-beta/#multiple-xcodeproj-generation) mode and fabric is on. since we have multiple pod projects, there are something breaks.

### `-DRCT_NEW_ARCH_ENABLED=1` does not pass to `RCTAppSetupUtils.mm`

because `installer.pods_project` is targeting `Pods.xcodeproj` but not `React-Core.xcodeproj`. we should use ` installer.target_installation_results.pod_target_installation_results` to deal with `generate_multiple_pod_projects` mode.

### fatal error: 'CompactValue.h' file not found

```
In file included from /path/to/react-native/packages/rn-tester/build/generated/ios/react/renderer/components/rncore/Props.cpp:11:
In file included from /path/to/react-native/packages/rn-tester/Pods/Headers/Private/React-Codegen/react/renderer/components/rncore/Props.h:13:
In file included from /path/to/react-native/packages/rn-tester/Pods/Headers/Private/React-Fabric/react/renderer/components/view/ViewProps.h:11:
In file included from /path/to/react-native/packages/rn-tester/Pods/Headers/Private/React-Fabric/react/renderer/components/view/YogaStylableProps.h:10:
/path/to/react-native/packages/rn-tester/Pods/Headers/Public/Yoga/yoga/YGStyle.h:16:10: fatal error: 'CompactValue.h' file not found
#include "CompactValue.h"
         ^~~~~~~~~~~~~~~~
1 error generated.
```

`Props.cpp` -> `YogaStylableProps.h` -> `YGStyle.h` -> `CompactValue.h`
[`CompactValue.h` is internal private header for Yoga pod](https://github.com/facebook/react-native/blob/4eef075a583224ec9da6bbc4b42bc52508eb31be/ReactCommon/yoga/Yoga.podspec#L54-L56) where `React-Codegen` project cannot access to.

~there are some solutions toward this problem. one way is to make other yoga headers as public headers. i am not sure whether this solution would introduce any side effects. so i only make necessary projects to search yoga private headers.~

Update: a solution is to expose all yoga headers publicly.  however, CocoaPods will put all public headers to module umbrella header. this will break YogaKit (swift) integration because swift module doesn't support c++. my pr is trying to expose all yoga headers to `$PODS_ROOT/Headers/Public/Yoga/yoga`, but use custom `module_map` to control which headers should be exposed to the swift module. CocoaPods's custom module_map has some limitation where cannot well support for both `use_frameworks!` mode and non use_frameworks! mode. there's a workaround to use `script_phase` copying the umbrella header to right place.

## Changelog

[iOS] [Fixed] - Fix iOS build error when Podfile `generate_multiple_pod_projects=true` and Fabric is on

Pull Request resolved: facebook#33381

Test Plan:
verify with rn-tester

1. add `generate_multiple_pod_projects`

```diff
 --- a/packages/rn-tester/Podfile
+++ b/packages/rn-tester/Podfile
@@ -5,7 +5,7 @@ platform :ios, '11.0'

 # Temporary solution to suppress duplicated GUID error.
 # Can be removed once we move to generate files outside pod install.
-install! 'cocoapods', :deterministic_uuids => false
+install! 'cocoapods',  :generate_multiple_pod_projects => true, :deterministic_uuids => false

 USE_FRAMEWORKS = ENV['USE_FRAMEWORKS'] == '1'

```

2. pod install and build rn-tester from xcode

Reviewed By: cortinico

Differential Revision: D34844041

Pulled By: dmitryrykun

fbshipit-source-id: 93311b56d8e44491307a911ad58442f267c979eb

ReactCommon/yoga/Yoga-umbrella.h

@@ -0,0 +1,21 @@
+#ifdef __OBJC__
+#import <UIKit/UIKit.h>
+#else
+#ifndef FOUNDATION_EXPORT
+#if defined(__cplusplus)
+#define FOUNDATION_EXPORT extern "C"
+#else
+#define FOUNDATION_EXPORT extern
+#endif
+#endif
+#endif
+
+#import "yoga/YGEnums.h"
+#import "yoga/YGMacros.h"
+#import "yoga/YGNode.h"
+#import "yoga/YGStyle.h"
+#import "yoga/YGValue.h"
+#import "yoga/Yoga.h"
+
+FOUNDATION_EXPORT double yogaVersionNumber;
+FOUNDATION_EXPORT const unsigned char yogaVersionString[];

ReactCommon/yoga/Yoga.modulemap

@@ -0,0 +1,6 @@
+framework module yoga {
+  umbrella header "Yoga-umbrella.h"
+
+  export *
+  module * { export * }
+}

ReactCommon/yoga/Yoga.podspec

@@ -47,11 +47,25 @@ Pod::Spec.new do |spec|
 
   # Set this environment variable when *not* using the `:path` option to install the pod.
   # E.g. when publishing this spec to a spec repo.
-  source_files = 'yoga/**/*.{cpp,h}'
-  source_files = File.join('ReactCommon/yoga', source_files) if ENV['INSTALL_YOGA_WITHOUT_PATH_OPTION']
+  source_files = 'yoga/**/*.{cpp,h}', 'Yoga-umbrella.h'
+  source_files = source_files.map { |file| File.join('ReactCommon/yoga', file) } if ENV['INSTALL_YOGA_WITHOUT_PATH_OPTION']
   spec.source_files = source_files
 
-  header_files = 'yoga/{Yoga,YGEnums,YGMacros,YGNode,YGStyle,YGValue}.h'
-  header_files = File.join('ReactCommon/yoga', header_files) if ENV['INSTALL_YOGA_WITHOUT_PATH_OPTION']
-  spec.public_header_files = header_files
+  spec.module_map = 'Yoga.modulemap'
+
+  # CocoaPods custom `module_map` + `header_dir` doesn't put the umbrella header in right place.
+  # Ideally, modulemap should be placed with the umbrella header, that would work for both use_frameworks! mode and non use_frameworks! mode.
+  # This script copy the umbrella header back to right place.
+  spec.script_phase = {
+    :name => 'Copy umbrella header',
+    :input_files => ["$PODS_ROOT/Headers/Public/Yoga/yoga/Yoga-umbrella.h"],
+    :output_files => ["$PODS_ROOT/Headers/Private/Yoga/Yoga-umbrella.h"],
+    :execution_position => :before_compile,
+    :shell_path => '/bin/bash',
+
+    # In use_frameworks! mode, the umbrella header will by copied to right place.
+    # This copy command will fail because "$PODS_ROOT/Headers/Public/Yoga/yoga/Yoga-umbrella.h" doesn't exist.
+    # The command is just a no-op in use_frameworks! mode.
+    :script => 'cp -f "$PODS_ROOT/Headers/Public/Yoga/yoga/Yoga-umbrella.h" "$PODS_ROOT/Headers/Private/Yoga/Yoga-umbrella.h" || true',
+  }
 end

scripts/react_native_pods.rb

@@ -287,12 +287,12 @@ def modify_flags_for_new_architecture(installer, cpp_flags)
           config_file.save_as(xcconfig_path)
       end
   end
-  # Add RCT_NEW_ARCH_ENABLED to Pods project xcconfig
-  installer.pods_project.targets.each do |target|
-    # if target.name == 'React-Core'
-    if target.name == 'React-Core'
-      puts "#{target.name}"
-      target.build_configurations.each do |config|
+
+  # Add RCT_NEW_ARCH_ENABLED to generated pod target projects
+  installer.target_installation_results.pod_target_installation_results
+    .each do |pod_name, target_installation_result|
+    if pod_name == 'React-Core'
+      target_installation_result.native_target.build_configurations.each do |config|
         config.build_settings['OTHER_CPLUSPLUSFLAGS'] = cpp_flags
       end
     end