Remove deprecated bitcode stripping from tooling (#140903)

Bitcode has been removed https://github.com/flutter/flutter/issues/107887, clean up the leftover commands.

packages/flutter_tools/lib/src/build_system/targets/ios.dart

@@ -296,9 +296,6 @@ abstract class UnpackIOS extends Target {
       throw Exception('Binary $frameworkBinaryPath does not exist, cannot thin');
     }
     await _thinFramework(environment, frameworkBinaryPath, archs);
-    if (buildMode == BuildMode.release) {
-      await _bitcodeStripFramework(environment, frameworkBinaryPath);
-    }
     await _signFramework(environment, frameworkBinary, buildMode);
   }
 
@@ -376,26 +373,6 @@ abstract class UnpackIOS extends Target {
       throw Exception('Failed to extract $archs for $frameworkBinaryPath.\n${extractResult.stderr}\nRunning lipo -info:\n$lipoInfo');
     }
   }
-
-  /// Destructively strip bitcode from the framework. This can be removed
-  /// when the framework is no longer built with bitcode.
-  Future<void> _bitcodeStripFramework(
-    Environment environment,
-    String frameworkBinaryPath,
-  ) async {
-    final ProcessResult stripResult = await environment.processManager.run(<String>[
-      'xcrun',
-      'bitcode_strip',
-      frameworkBinaryPath,
-      '-r', // Delete the bitcode segment.
-      '-o',
-      frameworkBinaryPath,
-    ]);
-
-    if (stripResult.exitCode != 0) {
-      throw Exception('Failed to strip bitcode for $frameworkBinaryPath.\n${stripResult.stderr}');
-    }
-  }
 }
 
 /// Unpack the release prebuilt engine framework.

packages/flutter_tools/test/general.shard/build_system/targets/ios_test.dart

@@ -813,56 +813,6 @@ void main() {
       expect(processManager, hasNoRemainingExpectations);
     });
 
-    testWithoutContext('fails when bitcode strip fails', () async {
-      binary.createSync(recursive: true);
-
-      final Environment environment = Environment.test(
-        fileSystem.currentDirectory,
-        processManager: processManager,
-        artifacts: artifacts,
-        logger: logger,
-        fileSystem: fileSystem,
-        outputDir: outputDir,
-        defines: <String, String>{
-          kIosArchs: 'arm64',
-          kSdkRoot: 'path/to/iPhoneOS.sdk',
-        },
-      );
-
-      processManager.addCommands(<FakeCommand>[
-        FakeCommand(command: <String>[
-          'rsync',
-          '-av',
-          '--delete',
-          '--filter',
-          '- .DS_Store/',
-          'Artifact.flutterFramework.TargetPlatform.ios.release.EnvironmentType.physical',
-          outputDir.path,
-        ]),
-        lipoCommandNonFatResult,
-        lipoVerifyArm64Command,
-        FakeCommand(command: <String>[
-          'xcrun',
-          'bitcode_strip',
-          binary.path,
-          '-r',
-          '-o',
-          binary.path,
-        ], exitCode: 1, stderr: 'bitcode_strip error'),
-      ]);
-
-      await expectLater(
-        const ReleaseUnpackIOS().build(environment),
-        throwsA(isException.having(
-          (Exception exception) => exception.toString(),
-          'description',
-          contains('Failed to strip bitcode for output/Flutter.framework/Flutter.\nbitcode_strip error'),
-        )),
-      );
-
-      expect(processManager, hasNoRemainingExpectations);
-    });
-
     testWithoutContext('strips framework', () async {
       binary.createSync(recursive: true);
 

packages/flutter_tools/test/host_cross_arch.shard/ios_content_validation_test.dart

@@ -7,11 +7,9 @@ import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/utils.dart';
 import 'package:flutter_tools/src/build_info.dart';
-import 'package:flutter_tools/src/convert.dart';
 
 import '../integration.shard/test_utils.dart';
 import '../src/common.dart';
-import '../src/fake_process_manager.dart';
 
 void main() {
   group('iOS app validation', () {
@@ -157,9 +155,6 @@ void main() {
           ));
 
           expect(vmSnapshot.existsSync(), buildMode == BuildMode.debug);
-
-          // Builds should not contain deprecated bitcode.
-          expect(_containsBitcode(outputFlutterFrameworkBinary.path, processManager), isFalse);
         });
 
         testWithoutContext('Info.plist dart VM Service Bonjour service', () {
@@ -363,46 +358,3 @@ void main() {
      timeout: const Timeout(Duration(minutes: 7))
   );
 }
-
-bool _containsBitcode(String pathToBinary, ProcessManager processManager) {
-  // See: https://stackoverflow.com/questions/32755775/how-to-check-a-static-library-is-built-contain-bitcode
-  final ProcessResult result = processManager.runSync(<String>[
-    'otool',
-    '-l',
-    '-arch',
-    'arm64',
-    pathToBinary,
-  ]);
-  final String loadCommands = result.stdout as String;
-  if (!loadCommands.contains('__LLVM')) {
-    return false;
-  }
-  // Presence of the section may mean a bitcode marker was embedded (size=1), but there is no content.
-  if (!loadCommands.contains('size 0x0000000000000001')) {
-    return true;
-  }
-  // Check the false positives: size=1 wasn't referencing the __LLVM section.
-
-  bool emptyBitcodeMarkerFound = false;
-  //  Section
-  //  sectname __bundle
-  //  segname __LLVM
-  //  addr 0x003c4000
-  //  size 0x0042b633
-  //  offset 3932160
-  //  ...
-  final List<String> lines = LineSplitter.split(loadCommands).toList();
-  lines.asMap().forEach((int index, String line) {
-    if (line.contains('segname __LLVM') && lines.length - index - 1 > 3) {
-      final bool bitcodeMarkerFound = lines
-          .skip(index - 1)
-          .take(4)
-          .any((String line) => line.contains(' size 0x0000000000000001'));
-      if (bitcodeMarkerFound) {
-        emptyBitcodeMarkerFound = true;
-        return;
-      }
-    }
-  });
-  return !emptyBitcodeMarkerFound;
-}