Update typed arrays behavior to match ES6 rev 15. Remove TO_POSITIVE_INTEGER and throw on negative …

Update typed arrays behavior to match ES6 rev 15. Remove TO_POSITIVE_INTEGER and throw on negative length arguments.

R=rossberg@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=15298

[Dmitry Lomov (no reviews), 2013-06-24 11:21:37]

PTAL

[rossberg, 2013-06-24 12:36:02]

The pattern of doing TO_INTEGER and then testing for negative now occurs all
over the place. Would it make sense to keep TO_POSITIVE_INTEGER as an
abstraction and just change its implementation accordingly?

https://codereview.chromium.org/17572009/diff/2001/src/arraybuffer.js
File src/arraybuffer.js (right):

https://codereview.chromium.org/17572009/diff/2001/src/arraybuffer.js#newcode36
src/arraybuffer.js:36: var byteLength = IS_UNDEFINED(length) ? 0 :
TO_INTEGER(length);
Doesn't TO_INTEGER(undefined) yield 0 anyway?

https://codereview.chromium.org/17572009/diff/2001/src/typedarray.js
File src/typedarray.js (right):

https://codereview.chromium.org/17572009/diff/2001/src/typedarray.js#newcode40
src/typedarray.js:40: var offset = IS_UNDEFINED(byteOffset) ? 0 :
TO_INTEGER(byteOffset);
Same here

https://codereview.chromium.org/17572009/diff/2001/src/typedarray.js#newcode160
src/typedarray.js:160: function TypedArraySet(obj, offset) {
and here

https://codereview.chromium.org/17572009/diff/2001/src/typedarray.js#newcode227
src/typedarray.js:227: var offset = IS_UNDEFINED(byteOffset) ? 0 :
TO_INTEGER(byteOffset);
and here

[Dmitry Lomov (no reviews), 2013-06-24 13:34:46]

Good suggestions, all addressed.
Also changed ArrayBuffer.prototype.slice to accept fin < first and return empty
ArrayBuffer. This is consistent with TypedArray.prototype.subarray, and also
with current implementation in Chrome and Firefox. Filed
https://bugs.ecmascript.org/show_bug.cgi?id=1566.

[rossberg, 2013-06-24 13:43:43]

lgtm

[Dmitry Lomov (no reviews), 2013-06-24 13:59:02]

Committed patchset #3 manually as r15298 (presubmit successful).