* load.c (features_index_add): use rb_str_subseq() to specify C string
position properly to fix require non ascii path.
[ruby-core:53733] [Bug #8165]
* test/ruby/test_require.rb (TestRequire#test_require_nonascii_path):
a test for the above.
* test/ruby/test_require.rb (TestRequire#test_require_nonascii_path):
fix load path for encoding to run the test as stand-alone.
* test/ruby/test_require.rb (TestRequire#test_require_nonascii_path):
RUBY_PLATFORM should escape as Regexp,
because RUBY_PLATFORM may contain '.'.
merge revision(s) 40135,40148,40173: [Backport #8165]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40398 b2dd03c8-39d4-4d8f-98ff-823fe69b080e