Rename app.so -> app.dylib (#4522)

packages/flutter_tools/bin/xcode_backend.sh

diff --git a/packages/flutter_tools/bin/xcode_backend.sh b/packages/flutter_tools/bin/xcode_backend.sh
index 12cf8ec..c0791ad 100755
--- a/packages/flutter_tools/bin/xcode_backend.sh
+++ b/packages/flutter_tools/bin/xcode_backend.sh
@@ -58,7 +58,7 @@
   AssertExists $derived_dir
 
   RunCommand rm -f ${derived_dir}/Flutter.framework
-  RunCommand rm -f ${derived_dir}/app.so
+  RunCommand rm -f ${derived_dir}/app.dylib
   RunCommand rm -f ${derived_dir}/app.flx
   RunCommand cp -r ${framework_path}/Flutter.framework ${derived_dir}
   RunCommand pushd ${project_path}
@@ -89,9 +89,9 @@
       exit -1
     fi
 
-    RunCommand cp build/aot/app.so ${derived_dir}/app.so
+    RunCommand cp build/aot/app.dylib ${derived_dir}/app.dylib
   else
-    RunCommand eval "$(echo \"static const int Moo = 88;\" | xcrun clang -x c --shared -o ${derived_dir}/app.so -)"
+    RunCommand eval "$(echo \"static const int Moo = 88;\" | xcrun clang -x c --shared -o ${derived_dir}/app.dylib -)"
   fi
 
   local precompilation_flag=""

packages/flutter_tools/lib/src/commands/build_aot.dart

diff --git a/packages/flutter_tools/lib/src/commands/build_aot.dart b/packages/flutter_tools/lib/src/commands/build_aot.dart
index e5707de..279bd27 100644
--- a/packages/flutter_tools/lib/src/commands/build_aot.dart
+++ b/packages/flutter_tools/lib/src/commands/build_aot.dart
@@ -271,7 +271,7 @@
   // On iOS, we use Xcode to compile the snapshot into a dynamic library that the
   // end-developer can link into their app.
   if (platform == TargetPlatform.ios) {
-    printStatus('Building app.so...');
+    printStatus('Building app.dylib...');
 
     // These names are known to from the engine.
     const String kDartVmIsolateSnapshotBuffer = 'kDartVmIsolateSnapshotBuffer';
@@ -306,7 +306,7 @@
       ..addAll(commonBuildOptions)
       ..addAll(<String>['-c', kDartIsolateSnapshotBufferC, '-o', kDartIsolateSnapshotBufferO]));
 
-    String appSo = path.join(outputDir.path, 'app.so');
+    String appSo = path.join(outputDir.path, 'app.dylib');
 
     List<String> linkCommand = <String>['xcrun', 'clang']
       ..addAll(commonBuildOptions)
@@ -314,7 +314,7 @@
         '-dynamiclib',
         '-Xlinker', '-rpath', '-Xlinker', '@executable_path/Frameworks',
         '-Xlinker', '-rpath', '-Xlinker', '@loader_path/Frameworks',
-        '-install_name', '@rpath/app.so',
+        '-install_name', '@rpath/app.dylib',
         '-o', appSo,
         kDartVmIsolateSnapshotBufferO,
         kDartIsolateSnapshotBufferO,