Replace runTestCase with assert helpers [test/language/expressions/]

test/language/expressions/array/11.1.4-0.js

test/language/expressions/assignment/8.14.4-8-b_1.js

.../language/expressions/compound-assignment/11.13.2-12-s.js

.../language/expressions/compound-assignment/11.13.2-13-s.js

.../language/expressions/compound-assignment/11.13.2-14-s.js

.../language/expressions/compound-assignment/11.13.2-15-s.js

.../language/expressions/compound-assignment/11.13.2-16-s.js

.../language/expressions/compound-assignment/11.13.2-17-s.js

.../language/expressions/compound-assignment/11.13.2-18-s.js

.../language/expressions/compound-assignment/11.13.2-19-s.js

.../language/expressions/compound-assignment/11.13.2-20-s.js

.../language/expressions/compound-assignment/11.13.2-21-s.js

.../language/expressions/compound-assignment/11.13.2-22-s.js

test/language/expressions/greater-than/11.8.2-1.js

test/language/expressions/greater-than/11.8.2-2.js

test/language/expressions/greater-than/11.8.2-3.js

test/language/expressions/greater-than/11.8.2-4.js

test/language/expressions/less-than-or-equal/11.8.3-1.js

test/language/expressions/less-than-or-equal/11.8.3-2.js

test/language/expressions/less-than-or-equal/11.8.3-3.js