Replace runTestCase with assert helpers [test/language/function-code]

test/language/function-code/10.4.3-1-1-s.js

test/language/function-code/10.4.3-1-10-s.js

test/language/function-code/10.4.3-1-100-s.js

test/language/function-code/10.4.3-1-13-s.js

test/language/function-code/10.4.3-1-14-s.js

test/language/function-code/10.4.3-1-15-s.js

test/language/function-code/10.4.3-1-16-s.js

test/language/function-code/10.4.3-1-2-s.js

test/language/function-code/10.4.3-1-21-s.js

test/language/function-code/10.4.3-1-22-s.js

test/language/function-code/10.4.3-1-23-s.js

test/language/function-code/10.4.3-1-24-s.js

test/language/function-code/10.4.3-1-25-s.js

test/language/function-code/10.4.3-1-26-s.js

test/language/function-code/10.4.3-1-27-s.js

test/language/function-code/10.4.3-1-28-s.js

test/language/function-code/10.4.3-1-29-s.js

test/language/function-code/10.4.3-1-3-s.js

test/language/function-code/10.4.3-1-30-s.js

test/language/function-code/10.4.3-1-31-s.js