merge revision(s) 40606,40607,40635: [Backport #8375]

	test_scanner_events.rb: assert_location

	* test/ripper/test_scanner_events.rb (TestRipper#assert_location):
  rename so skipped in backtraces.
	* parse.y (parser_yylex): fail if $, @, @@ are not followed by a valid
	  name character.  [ruby-core:54846] [Bug #8375].

	* parse.y (parser_peek_variable_name): treat invalid global, class,
	  and instance variable names as mere strings rather than errors.
	  [ruby-core:54885] [Bug #8375]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40650 b2dd03c8-39d4-4d8f-98ff-823fe69b080e