ARM64: Rename TryConvertDoubleToInt64 function

There are two TryConvertDoubleToInt64 functions: one rounds, the other checks
if a double can be exactly represented as an int. This patch renames the second
instance to reflect its purpose more clearly.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/258933008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21020 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Convert function.caller to API-style accessor.

BUG=
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/256803010

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21021 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Tighten OpenHandle's extra checks.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/240113010

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21022 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/master'