Use assert api instead of $ERROR

.../built-ins/RegExp/RegExp-control-escape-russian-letter.js

...exB/built-ins/RegExp/RegExp-decimal-escape-class-range.js

...B/built-ins/RegExp/RegExp-decimal-escape-not-capturing.js

test/annexB/built-ins/escape/B.2.1.propertyCheck.js

test/annexB/built-ins/escape/prop-desc.js

test/annexB/built-ins/unescape/B.2.2.propertyCheck.js

test/annexB/built-ins/unescape/prop-desc.js