[turbofan] Run value numbering after SimplifiedLowering.

Running ValueNumberingReducer together with ChangeLowering causes
trouble with the current GraphReducer and makes GVN ineffective, so
running it before we get to change lowering works around that well-known
(phase ordering) problem for now.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/660733003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24656 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Implement .forEach() on typed arrays

BUG=v8:3578
LOG=Y
R=dslomov@chromium.org, wingo@igalia.com

Review URL: https://codereview.chromium.org/583723002

Patch from Adrian Perez de Castro <aperez@igalia.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24657 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Object.is should use SameValue

BUG=v8:3576
LOG=
R=arv@chromium.org, svenpanne@chromium.org, wingo@igalia.com

Review URL: https://codereview.chromium.org/626323002

Patch from Diego Pino <dpino@igalia.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24658 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix x64 after r24656.

TBR=jarin@chromium.org

Review URL: https://codereview.chromium.org/655383003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24659 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
[turbofan] Correctify typed lowering.

We cannot add new JSToNumber nodes here in general, because:

 a) The inserted ToNumber operation screws up observability of valueOf.
 b) Deoptimization at ToNumber doesn't have corresponding bailout id.

TEST=cctest,mjsunit
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/649543004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24660 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Eliminate special keyed load string stub in favor of uniform handlers.

KeyedLoadIC installs a special case if the receiver is a string.
Although there are several maps for strings, in practice we seem to
be able to treat them individually because a given KeyedLoad site
only sees 1-2 string types.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/602773003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24661 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix clang compilation error.

TBR=yangguo@chromium.org

Review URL: https://codereview.chromium.org/659053002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24662 ce2b1a6d-e550-0410-aec6-3dcde31c8c00