Update to mini_portile2 v2.8.3

This pulls in flavorjones/mini_portile#129.
When cross-compiling Windows targets with cmake in a Linux
environment, the MSYS generator may not be available. Supplying -G
MSYS will cause the build to fail.

ext/re2/extconf.rb

@@ -8,7 +8,7 @@
 
 PACKAGE_ROOT_DIR = File.expand_path(File.join(File.dirname(__FILE__), '..', '..'))
 
-REQUIRED_MINI_PORTILE_VERSION = "~> 2.8.2" # keep this version in sync with the one in the gemspec
+REQUIRED_MINI_PORTILE_VERSION = "~> 2.8.3" # keep this version in sync with the one in the gemspec
 
 RE2_HELP_MESSAGE = <<~HELP
   USAGE: ruby #{$0} [options]
@@ -135,22 +135,6 @@ def cmake_compile_flags(host)
   ]
 end
 
-# By default, mini_portile2 might add an unnecessary option:
-# https://github.com/flavorjones/mini_portile/blob/5084a2aeab12076f534cf0cabc81a4d5f84b5c25/lib/mini_portile2/mini_portile_cmake.rb#L17
-# See https://github.com/flavorjones/mini_portile/issues/127.
-def delete_cmake_generator_option!(options)
-  indices = []
-
-  options.each_with_index do |element, index|
-    if element == '-G' && index + 1 < options.length
-      indices << index
-      indices << index + 1
-    end
-  end
-
-  indices.reverse_each { |index| options.delete_at(index) }
-end
-
 #
 #  main
 #
@@ -277,7 +261,6 @@ def process_recipe(name, version)
       '-DCMAKE_INSTALL_LIBDIR=lib'
     ]
     recipe.configure_options += cmake_compile_flags(recipe.host)
-    delete_cmake_generator_option!(recipe.configure_options)
 
     yield recipe
 

re2.gemspec

@@ -32,5 +32,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency "rake-compiler", "~> 1.2.1"
   s.add_development_dependency "rake-compiler-dock", "~> 1.3.0"
   s.add_development_dependency("rspec", "~> 3.2")
-  s.add_runtime_dependency("mini_portile2", "~> 2.8.2") # keep version in sync with extconf.rb
+  s.add_runtime_dependency("mini_portile2", "~> 2.8.3") # keep version in sync with extconf.rb
 end