Mapped arguments property is changed to non-configurable. Check
arguments mapping works correctly when applying various MOP
methods.

- Add missing "var" declarations and noStrict flags
- Add strict mode tests for:
 - arguments-object/10.6-6-3 -> arguments-object/10.6-6-3-s
 - arguments-object/10.6-6-4 -> arguments-object/10.6-6-4-s
- Remove try-finally clean-up code
- Add strict mode compatible tests for eval-code/S10.4.2_A1.1_T*
  - No strict mode compatible files added for eval-code/S10.4.2_A1.2_T*, because it doesn't really make sense in this context.
  - (S10.4.2_A1.1 and S10.4.2_A1.2 should probably be removed, because the tested behaviour is not required by the spec.)
- Split S8.5_A10, S8.5_A4 and S8.1_A3 into declaration (both modes) and assignment tests (non-strict only)

Part of issue #35.

These tests are derived from the following files within the Google V8
project:

    test/mjsunit/es6/typed-array-iterator.js
    test/mjsunit/es6/arguments-iterator.js
    test/mjsunit/es6/string-iterator.js
    test/mjsunit/es6/collection-iterator.js