build: build squirrel and its dependencies from source (#24318)

* build: build squirrel and its dependencies from source

* chore: do not use fork for squirrel.mac

* build: do not ship headers with dependency frameworks

* Update BUILD.gn

* chore: s/striped/stripped

* chore: update as per feedback

* chore: use ARC and fix build errors

* chore: fix ARC Squirrel self retainer

DEPS

@@ -18,6 +18,8 @@ vars = {
     'v12.18.2',
   'nan_version':
     '2c4ee8a32a299eada3cd6e468bbd0a473bfea96d',
+  'squirrel.mac_version':
+    '44468f858ce0d25c27bd5e674abfa104e0119738',
 
   'boto_version': 'f7574aa6cc2c819430c1f05e9a1a1a666ef8169b',
   'pyyaml_version': '3.12',
@@ -29,6 +31,7 @@ vars = {
   'nodejs_git': 'https://github.com/nodejs',
   'requests_git': 'https://github.com/kennethreitz',
   'yaml_git': 'https://github.com/yaml',
+  'squirrel_git': 'https://github.com/Squirrel',
 
   # KEEP IN SYNC WITH utils.js FILE
   'yarn_version': '1.15.2',
@@ -101,6 +104,18 @@ deps = {
     'url': Var('requests_git') + '/requests.git' + '@' +  Var('requests_version'),
     'condition': 'checkout_requests and process_deps',
   },
+  'src/third_party/squirrel.mac': {
+    'url': Var("squirrel_git") + '/Squirrel.Mac.git@' + Var("squirrel.mac_version"),
+    'condition': 'process_deps',
+  },
+  'src/third_party/squirrel.mac/vendor/ReactiveObjC': {
+    'url': 'https://github.com/ReactiveCocoa/ReactiveObjC.git@74ab5baccc6f7202c8ac69a8d1e152c29dc1ea76',
+    'condition': 'process_deps'
+  },
+  'src/third_party/squirrel.mac/vendor/Mantle': {
+    'url': 'https://github.com/Mantle/Mantle.git@78d3966b3c331292ea29ec38661b25df0a245948',
+    'condition': 'process_deps',
+  }
 }
 
 hooks = [
@@ -156,4 +171,5 @@ hooks = [
 
 recursedeps = [
   'src',
+  'src/third_party/squirrel.mac',
 ]