Update tests to use assertion library

test/language/expressions/typeof/boolean.js

test/language/expressions/typeof/built-in-functions.js

test/language/expressions/typeof/get-value.js

test/language/expressions/typeof/native-call.js

test/language/expressions/typeof/native-no-call.js

test/language/expressions/typeof/null.js

test/language/expressions/typeof/number.js

test/language/expressions/typeof/string.js

test/language/expressions/typeof/syntax.js

test/language/expressions/typeof/undefined.js

test/language/expressions/typeof/unresolvable-reference.js