windows: split into 2 tasks

Rakefile

@@ -148,11 +148,30 @@ namespace :clean do
   end
 end
 
+def target_rubies
+  "2.0.0:2.1.6:2.2.2"
+end
+
 desc "Build cross compile binary with rake-compiler-dock"
 namespace :build do
-  task :windows do
+  task :windows => [:windows_x86, :windows_x64]
+end
+
+desc "Build cross compile binary with rake-compiler-dock for i386"
+namespace :build do
+  task :windows_x86 do
+    require "rake_compiler_dock"
+    rm_rf binary_dir
+    RakeCompilerDock.sh "gem install yard packnga pkg-config && bundle && bundle exec rake clean && rake cross native gem RUBY_CC_VERSION=#{target_rubies}"
+  end
+end
+
+desc "Build cross compile binary with rake-compiler-dock for x64"
+namespace :build do
+  task :windows_x64 do
     require "rake_compiler_dock"
-    RakeCompilerDock.sh "bundle && rake cross native gem RUBY_CC_VERSION=2.0.0:2.1.6:2.2.2"
+    rm_rf binary_dir
+    RakeCompilerDock.sh "gem install yard packnga pkg-config && bundle && bundle exec rake clean && RROONGA_USE_GROONGA_X64=true rake cross native gem RUBY_CC_VERSION=#{target_rubies}"
   end
 end