unicode_norm_gen.rb: optimize concatenation

* tool/unicode_norm_gen.rb: optimization by string literal
  concatenation instead of runtime concatenation.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47813 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
unicode_norm_gen.rb: us-ascii

* tool/unicode_norm_gen.rb (Integer#to_UTF8): escape non-ascii
  code.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47814 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
unicode_norm_gen.rb: freeze

* tool/unicode_norm_gen.rb: freeze strings and tables.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47815 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
symbol.c: junk-base attrset

* symbol.c (rb_enc_symname_type): allow junk-base attrset ID
  unless the stem is not an attrset name.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47816 b2dd03c8-39d4-4d8f-98ff-823fe69b080e