test: rewrite spawnsync test

The spawnsync test was written wrong, the timeout can never fire before
the sync process has returned, the delta is immaterial and times when
it was succeeding are not reliable cases.

Instead verify that the timeout doesn't fire while the sync process is
happening.
tls_wrap: do not store TLSCallbacks in SSL_CTX

Storing it in SSL_CTX is incorrect as it may go away and get destructed
earlier, also it'll yield invalid results in SelectSNIContextCallback.

Use `SSL_get_app_data()` instead.

fix #7484

Signed-off-by: Timothy J Fontaine <tjfontaine@gmail.com>
string_bytes: ucs2 support big endian

64bit constants are keyed for x64 platforms only, add PowerPC based
platform constants.

Node's "ucs2" encoding wants LE character data stored in the Buffer, so
we need to reorder on BE platforms.  See
http://nodejs.org/api/buffer.html regarding Node's "ucs2" encoding
specification

Signed-off-by: Timothy J Fontaine <tjfontaine@gmail.com>
v8: backport no handle zapping for release builds

BUG=318206
LOG=y
R=danno@chromium.org

Review URL: https://codereview.chromium.org/295673002

git-svn-id: https://v8.googlecode.com/svn/branches/3.26@21367 ce2b1a6d-e550-0410-aec6-3dcde31c8c00