Move two files from 'early' to 'fail' after merge of PR #2392

Each of the two tests:
  early/1447683fba196181.js
  early/d52f769ab39372c7.js
consists of a RegularExpressionLiteral in which the RegularExpressionFlags
contains a UnicodeEscapeSequence.

Formerly, this was disallowed via an Early Error,
but with the merge of tc39/ecma262#2392,
it is now disallowed via the grammar.
Thus, these tests should move from 'early' to 'fail'.

Author: jmdyck