New Compilation API, part 1, try 2

- Distinguish between context bound scripts (Script) and context unbound scripts
(UnboundScript).
- Add ScriptCompiler (which will later contain functions for async compilation).

This is a breaking change, in particular, Script::New no longer exists (it is
replaced by ScriptCompiler::CompileUnbound). Script::Compile remains as a
backwards-compatible shorthand for ScriptCompiler::Compile.

Passing CompilerOptions with produce_data_to_cache = true doesn't do anything
yet; the only way to generate the data to cache is the old preparsing API. (To
be fixed in the next version.)

This is a fixed version of https://codereview.chromium.org/186723005/

BUG=
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/199063003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19925 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix for issue 351261.

This relands the following fix: "HAllocate should never generate
allocation code if the requested size does not fit into page. Regression
test included. (bug 347543)" along with additional fixes to KeyedStoreIC.

BUG=351261
LOG=N
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/200113002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19926 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A64: Fix a few simulation inaccuracies.

  - Return the correct NaN when an invalid operation generates a NaN.
  - When one or more operands are NaN, handle them as the processor
    would, prioritising signalling NaNs and making them quiet.
  - Fix fmadd and related instructions:
     - Fnmadd is fma(-n, m, -a), not -fma(n, m, a).
     - Some common libc implementations incorrectly implement fma for
       zero results, so work around these cases.
  - Replace some unreliable tests.

This patch also adds support for Default-NaN mode, since once all the
other work was done, it only required a couple of lines of code.
Default-NaN mode was used for an optimisation in ARM, and it should now
be possible to apply the same optimisation to A64.

BUG=
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/199083005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19927 ce2b1a6d-e550-0410-aec6-3dcde31c8c00