Rename and consolidate tests in reserved-words directory

test/language/reserved-words/7.6.1-3-2.js

test/language/reserved-words/7.6.1-3-3.js

test/language/reserved-words/7.6.1-3-4.js

test/language/reserved-words/7.6.1-3-5.js

test/language/reserved-words/7.6.1-3-6.js

test/language/reserved-words/7.6.1-3-7.js

test/language/reserved-words/7.6.1-3-8.js

test/language/reserved-words/7.6.1-3-9.js

test/language/reserved-words/7.6.1-4-1.js

test/language/reserved-words/7.6.1-4-10.js

test/language/reserved-words/7.6.1-4-11.js

test/language/reserved-words/7.6.1-4-12.js

test/language/reserved-words/7.6.1-4-13.js

test/language/reserved-words/7.6.1-4-14.js

test/language/reserved-words/7.6.1-4-15.js

test/language/reserved-words/7.6.1-4-16.js

test/language/reserved-words/7.6.1-4-2.js

test/language/reserved-words/7.6.1-4-3.js

test/language/reserved-words/7.6.1-4-4.js

test/language/reserved-words/7.6.1-4-5.js