Tighten up Object.observe code to ASSERT that it never deals with globals

After r21126, Object.observe no longer allows observing the global proxy
object. This patch replaces codepaths that used to handle that case with
asserts showing that no such observation happens.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/261773006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21151 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Next bunch of fixes for check elimination.

- Canonicalize HCheckMapValue with constant map to
  HCheckMaps, and get rid of the special treatment
  during check elimination.
- Track only stable object maps for HConstants and
  add CHECK()s to verify state during code generation.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/263923004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21154 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix Mac64-debug issue introduced with r21154.

R=ishell@chromium.org

Review URL: https://codereview.chromium.org/271443002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21155 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
ARM64: Use default-NaN mode to canonicalize NaNs.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/255343004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21156 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Make sure CPU profiler collects a sample on start.

BUG=369035
LOG=N
R=bmeurer@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/263883008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21157 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Do not call setters of read-only accessors.

BUG=
TEST=mjsunit/readonly-accessor
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/271433002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21158 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
[Android]: Update Makefile.android to use platform-14 as minimum.

The version of the NDK in Chromium only has platform/android-14 and above
(since Chrome only supports API 14 and above).  To make it easier for
developers to use the Chromium NDK to build V8, this CL updates the default
platform version to 14.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/267873002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21159 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove broken %_Log functionality.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/265283007

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21160 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/bleeding_edge' into bleeding_edge