Replace runTestCase with assert helpers [test/language/statements/for]

test/language/statements/for/12.6.3_2-3-a-ii-1.js

test/language/statements/for/12.6.3_2-3-a-ii-10.js

test/language/statements/for/12.6.3_2-3-a-ii-11.js

test/language/statements/for/12.6.3_2-3-a-ii-12.js

test/language/statements/for/12.6.3_2-3-a-ii-13.js

test/language/statements/for/12.6.3_2-3-a-ii-14.js

test/language/statements/for/12.6.3_2-3-a-ii-15.js

test/language/statements/for/12.6.3_2-3-a-ii-16.js

test/language/statements/for/12.6.3_2-3-a-ii-17.js

test/language/statements/for/12.6.3_2-3-a-ii-18.js

test/language/statements/for/12.6.3_2-3-a-ii-19.js

test/language/statements/for/12.6.3_2-3-a-ii-2.js

test/language/statements/for/12.6.3_2-3-a-ii-20.js

test/language/statements/for/12.6.3_2-3-a-ii-21.js

test/language/statements/for/12.6.3_2-3-a-ii-3.js

test/language/statements/for/12.6.3_2-3-a-ii-4.js

test/language/statements/for/12.6.3_2-3-a-ii-5.js

test/language/statements/for/12.6.3_2-3-a-ii-6.js

test/language/statements/for/12.6.3_2-3-a-ii-7.js

test/language/statements/for/12.6.3_2-3-a-ii-8.js