update to 8.4.371.19

This requires changing our checkout strategy to check out the branch-heads branch (as documented at https://v8.dev/docs/version-numbers) instead of using the 8.4.371 branch, which never gets patches (it's always locked to 8.4.371.0).

We could also specify the v8 patch version manually, and i'm open to doing that, just wanted to do this to get it working.

Author: nightpool

ext/libv8/builder.rb

@@ -65,7 +65,7 @@ def setup_python!
     # then this will be 4.5.95
     #
     def source_version
-      Libv8::VERSION.gsub(/\.[^.]+$/, '')
+      Libv8::V8_MINOR_VERSION
     end
 
     ##
@@ -84,7 +84,7 @@ def setup_build_deps!
 
         Dir.chdir('v8') do
           system 'git fetch origin'
-          unless system "git checkout #{source_version}"
+          unless system "git checkout branch-heads/#{source_version}"
             fail "unable to checkout source for v8 #{source_version}"
           end
           system "gclient sync" or fail "could not sync v8 build dependencies"

lib/libv8/version.rb

@@ -1,3 +1,4 @@
 module Libv8
-  VERSION = "7.3.495.0"
+  V8_MINOR_VERSION = "8.4"
+  VERSION = "8.4.371.0"
 end