Remove some unused variables

bin/natalie

@@ -278,7 +278,6 @@ class Runner
   end
 
   def run_temp_and_wait(path)
-    build_dir = File.expand_path('../build', __dir__)
     var_name = RbConfig::CONFIG['LIBPATHENV']
     env = { var_name => Natalie::Compiler::CppBackend::LIB_PATHS.join(':') }
     pid = spawn(env, path, *ARGV)

lib/natalie/compiler/backends/cpp_backend/transform.rb

@@ -201,7 +201,7 @@ def add_file(name)
 
         def value_has_side_effects?(value)
           return false if value =~ /^Value\((False|Nil|True)Object::the\(\)\)$/
-          return false if value =~ /^Value\([\w_]*symbols\[\d+\]\/\*\:[^\*]+\*\/\)$/
+          return false if value =~ /^Value\(\w*symbols\[\d+\]\/\*\:[^\*]+\*\/\)$/
           true
         end
 

lib/natalie/compiler/bytecode/ro_data.rb

@@ -23,7 +23,6 @@ def self.load(str)
         def add(value)
           return @add_lookup[value] if @add_lookup.key?(value)
 
-          size = value.bytesize
           position = @buffer.size
           @buffer << [value.bytesize].pack('w')
           @buffer << value.b

lib/natalie/compiler/instructions/create_range_instruction.rb

@@ -30,7 +30,6 @@ def execute(vm)
       end
 
       def serialize(_)
-        name_string = @name.to_s
         [
           instruction_number,
           @exclude_end ? 1 : 0,

lib/optparse.rb

@@ -114,7 +114,8 @@ def initialize
     yield self if block_given?
   end
 
-  attr_accessor :banner, :program_name, :version
+  attr_accessor :banner, :program_name
+  attr_writer :version
 
   def on(*args, options: nil, &block)
     short_name, short_value = args.grep(/^\-[^\-]/).first&.split(/[ =]/, 2)