es6 compatability updates

test/suite/ch11/11.2/11.2.1/S11.2.1_A4_T5.js

test/suite/ch11/11.4/11.4.1/11.4.1-5-a-28-s.js

test/suite/ch12/12.1/S12.1_A4_T2.js

test/suite/ch12/12.14/12.14-1.js

test/suite/ch12/12.14/12.14-2.js

test/suite/ch13/13.2/13.2-15-1.js

test/suite/ch15/15.1/15.1.2/15.1.2.1/S15.1.2.1_A4.2.js

test/suite/ch15/15.1/15.1.2/15.1.2.2/S15.1.2.2_A9.2.js

test/suite/ch15/15.1/15.1.2/15.1.2.3/S15.1.2.3_A7.2.js

test/suite/ch15/15.1/15.1.2/15.1.2.4/S15.1.2.4_A2.2.js

test/suite/ch15/15.1/15.1.2/15.1.2.5/S15.1.2.5_A2.2.js

test/suite/ch15/15.1/15.1.3/15.1.3.1/S15.1.3.1_A5.2.js

test/suite/ch15/15.1/15.1.3/15.1.3.2/S15.1.3.2_A5.2.js

test/suite/ch15/15.1/15.1.3/15.1.3.3/S15.1.3.3_A5.2.js

test/suite/ch15/15.1/15.1.3/15.1.3.4/S15.1.3.4_A5.2.js

test/suite/ch15/15.10/15.10.6/15.10.6.2/S15.10.6.2_A9.js

test/suite/ch15/15.10/15.10.6/15.10.6.3/S15.10.6.3_A9.js

test/suite/ch15/15.10/15.10.6/15.10.6.4/S15.10.6.4_A9.js

test/suite/ch15/15.10/15.10.6/15.10.6.js

test/suite/ch15/15.10/15.10.7/15.10.7.1/15.10.7.1-1.js