Upgrade V8 to 7.9.8 (#2907)

//build was updated and our patch rebased:
https://github.com/denoland/chromium_build/tree/20190910_win_clang_depfile

V8 has removed the binaries third_party/v8/buildtools/*/gn.sha1 and started 
using CIPD. In this patch, I've hacked in the original .sha1 files and continue to
use download_from_google_storage instead of the new CIPD. This will be fixed
in later work.

.appveyor.yml

@@ -186,6 +186,7 @@ before_build:
       $env:AWS_SECRET_ACCESS_KEY = $null
 
 build_script:
+  - python tools\setup.py
   - cargo clippy --all-targets --release --locked -- -D clippy::all
   - cargo build -vv --release --all-targets --locked
 

.travis.yml

@@ -65,6 +65,7 @@ jobs:
   include:
     - name: "release mac x86_64"
       os: osx
+      osx_image: xcode11
       after_success:
         - &gzip_release
           gzip -c target/release/deno > target/release/deno_${TRAVIS_OS_NAME}_x64.gz

build

@@ -1 +1 @@
-Subproject commit 7b594236fbba04ee23d32ba3adf5ea68611cf2e7
+Subproject commit 6af664c48ed657b89e99a9a8692dc15d7f7a6d9c

gclient_config.py

@@ -1,7 +1,7 @@
 # Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 solutions = [{
     'url':
-    'https://chromium.googlesource.com/v8/v8.git@7.7.200',
+    'https://chromium.googlesource.com/v8/v8.git@7.9.8',
     'name': 'v8',
     'deps_file': 'DEPS',
     'custom_deps': {

third_party

@@ -1 +1 @@
-Subproject commit c3b4aceb2444180334634aa5eb70580bfe592e11
+Subproject commit f8757afb7368b2f6a518ebedde728f819e7c59d0

tools/third_party.py

@@ -20,6 +20,8 @@ def tp(*subpath_parts):
     return root("third_party", *subpath_parts)
 
 
+build_path = root("build")
+
 third_party_path = tp()
 depot_tools_path = tp("depot_tools")
 rust_crates_path = tp("rust_crates")
@@ -52,6 +54,7 @@ def python_env(env=None, merge_env=None):
         python_site_env = {}
         temp = os.environ["PATH"], sys.path
         os.environ["PATH"], sys.path = "", []
+        site.addsitedir(build_path)  # Modifies PATH and sys.path.
         site.addsitedir(python_packages_path)  # Modifies PATH and sys.path.
         python_site_env = {"PATH": os.environ["PATH"], "PYTHONPATH": sys.path}
         os.environ["PATH"], sys.path = temp