[TF] Simplify tensorflow_osx_base build preset. (#29947)

Previously, the `tensorflow_osx_base` preset duplicated all options from
from the `buildbot_osx_package` preset. This was not ideal:
`tensorflow_osx_base` was not robust against changes to `buildbot_osx_package`
and broke when changes were not copied.

Now, `tensorflow_osx_base` directly uses `buildbot_osx_package` as a mixin.

Updating `update-checkout-config.json` was necessary to make
`build-toolchain-tensorflow` pass.

Resolves TF-941.

Author: dan-zheng

utils/build-presets.ini

@@ -2328,84 +2328,29 @@ no-assertions
 [preset: mixin_codesigning]
 darwin-toolchain-application-cert=lldb_codesign
 
-# Note: `tensorflow_osx_base` does not mix in `buildbot_osx_package` because
-# they enable ios/tvos/watchos by default. Instead, options are copied here
-# individually.
-# TODO(TF-941): Try to mixin `buildbot_osx_package` directly. This requires
-# options like `skip-ios` to override `ios`.
 [preset: tensorflow_osx_base]
-mixin-preset=mixin_lightweight_assertions
-
-### From: mixin_osx_package_base
-lldb
-llbuild
-swiftpm
-swiftsyntax
-skstresstester
-playgroundsupport
-libcxx
-indexstore-db
-sourcekit-lsp
-
-release-debuginfo
-
-lldb-no-debugserver
-lldb-use-system-debugserver
-lldb-build-type=Release
-verbose-build
-build-ninja
-build-swift-stdlib-unittest-extra
-playgroundsupport-build-type=Release
-
-install-swift
-install-lldb
-install-llbuild
-install-swiftpm
-install-swiftsyntax
-install-skstresstester
-install-swiftevolve
-install-playgroundsupport
-
-darwin-install-extract-symbols
-# Path where toolchain will be installed.
-install-destdir=%(install_destdir)s
-# Path where debug symbols will be installed.
-install-symroot=%(install_symroot)s
-# Path where the compiler + runtime + standard libraries will be installed.
-install-prefix=%(install_toolchain_dir)s/usr
-# Execute lit tests from swift-integration-tests repository.
-test-installable-package
-# Force reconfiguration.
-reconfigure
-
-swift-install-components=compiler;clang-resource-dir-symlink;stdlib;sdk-overlay;parser-lib;toolchain-tools;license;sourcekit-xpc-service;swift-remote-mirror;swift-remote-mirror-headers
-llvm-install-components=llvm-cov;llvm-profdata;IndexStore;clang;clang-resource-headers;compiler-rt;clangd;dsymutil
-install-libcxx
-
-# Path to the .tar.gz package.
-installable-package=%(installable_package)s
-# Path to the .tar.gz symbols package.
-symbols-package=%(symbols_package)s
-# Info.plist
-darwin-toolchain-bundle-identifier=%(darwin_toolchain_bundle_identifier)s
-darwin-toolchain-display-name=%(darwin_toolchain_display_name)s
-darwin-toolchain-display-name-short=%(darwin_toolchain_display_name_short)s
-darwin-toolchain-name=%(darwin_toolchain_xctoolchain_name)s
-darwin-toolchain-version=%(darwin_toolchain_version)s
-darwin-toolchain-alias=%(darwin_toolchain_alias)s
+mixin-preset=buildbot_osx_package
 
-### TensorFlow custom options.
 build-subdir=buildbot_osx
 compiler-vendor=none
+
+# Skip SwiftSyntax verification.
+# TODO: Remove this when `utils/gyb_syntax_support` has no diff with master.
+swiftsyntax-verify-generated-files=0
+
 # Skip benchmarks.
 skip-build-benchmarks
+
 # Target only macOS.
+# Note: these `skip-{i,tv,watch}os` flags override `{i,tv,watch}os` flags from
+# the `buildbot_osx_package` preset.
 skip-ios
 skip-tvos
 skip-watchos
 stdlib-deployment-targets=macosx-x86_64
 swift-primary-variant-sdk=OSX
 swift-primary-variant-arch=x86_64
+
 # Enable TensorFlow support.
 enable-tensorflow
 install-tensorflow

utils/update_checkout/update-checkout-config.json

@@ -310,21 +310,21 @@
             "repos": {
                 "llvm-project": "b3057cffb63ed229b4552d57264414b4419fdb47",
                 "swift": "tensorflow",
-                "cmark": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "llbuild": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
+                "cmark": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "llbuild": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
                 "swift-tools-support-core": "0.0.1",
-                "swiftpm": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
+                "swiftpm": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
                 "swift-syntax": "1e524b3edc47e8ff66890d914b8bcd024e061631",
-                "swift-stress-tester": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "swift-corelibs-xctest": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "swift-corelibs-foundation": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "swift-corelibs-libdispatch": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "swift-integration-tests": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "swift-xcode-playground-support": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
+                "swift-stress-tester": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "swift-corelibs-xctest": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "swift-corelibs-foundation": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "swift-corelibs-libdispatch": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "swift-integration-tests": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "swift-xcode-playground-support": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
                 "ninja": "release",
                 "icu": "release-65-1",
-                "indexstore-db": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
-                "sourcekit-lsp": "swift-DEVELOPMENT-SNAPSHOT-2020-01-31-a",
+                "indexstore-db": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
+                "sourcekit-lsp": "swift-DEVELOPMENT-SNAPSHOT-2020-02-12-a",
                 "swift-format": "master",
                 "tensorflow": "v2.1.0-rc1",
                 "tensorflow-swift-apis": "9a47e3cb71c798938b127729853d5911315a1d6e",