Build unstable against v8 >= 3.25.2; broken >= 3.25.12

[stesie]

After fixing #83 the build is now broken for v8 version 3.25.12 and higher:

+ make
/bin/bash /var/lib/jenkins/workspace/v8js-with-v8-3.25.12/libtool --mode=compile g++ -std=c++11 -I. -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12 -DPHP_ATOM_INC -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/include -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/main -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12 -I/usr/include/php5 -I/usr/include/php5/main -I/usr/include/php5/TSRM -I/usr/include/php5/Zend -I/usr/include/php5/ext -I/usr/include/php5/ext/date/lib -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8-3.25.12//include  -DHAVE_CONFIG_H  -g -O2   -c /var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc -o v8js.lo 
libtool: compile:  g++ -std=c++11 -I. -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12 -DPHP_ATOM_INC -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/include -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/main -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12 -I/usr/include/php5 -I/usr/include/php5/main -I/usr/include/php5/TSRM -I/usr/include/php5/Zend -I/usr/include/php5/ext -I/usr/include/php5/ext/date/lib -I/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8-3.25.12//include -DHAVE_CONFIG_H -g -O2 -c /var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc  -fPIC -DPIC -o .libs/v8js.o
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:61:1: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc: In function 'void zim_V8Object___construct(int, zval*, zval**, zval*, int)':
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:516:54: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc: In function 'void zim_V8Function___construct(int, zval*, zval**, zval*, int)':
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:526:54: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc: In function 'void zim_V8Js_executeString(int, zval*, zval**, zval*, int)':
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:1033:33: error: 'New' is not a member of 'v8::Script'
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc: In function 'void php_v8js_persistent_zval_ctor(zval**)':
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:1239:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc: In function 'void php_v8js_persistent_zval_dtor(zval**)':
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:1252:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc: At global scope:
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:1399:1: warning: narrowing conversion of '-1' from 'int' to 'zend_uint {aka unsigned int}' inside { } [-Wnarrowing]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:1413:1: warning: narrowing conversion of '-1' from 'int' to 'zend_uint {aka unsigned int}' inside { } [-Wnarrowing]
/var/lib/jenkins/workspace/v8js-with-v8-3.25.12/v8js.cc:1416:1: warning: narrowing conversion of '-1' from 'int' to 'zend_uint {aka unsigned int}' inside { } [-Wnarrowing]
make: *** [v8js.lo] Error 1
Build step 'Execute shell' marked build as failure
Recording test results
Sending e-mails to: stesie@brokenpipe.de
Finished: FAILURE

However it is already unstable since 3.25.2, since they added some memory leak assertion wrt. weak refs, which "crashes" the module shutdown

#
# Fatal error in ../src/global-handles.cc, line 274
# CHECK(state() != NEAR_DEATH) failed
#

==== C stack trace ===============================

 1: v8::internal::GlobalHandles::PostGarbageCollectionProcessing(v8::internal::GarbageCollector, v8::internal::GCTracer*)
 2: v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::internal::GCTracer*, v8::GCCallbackFlags)
 3: v8::internal::Heap::CollectGarbage(v8::internal::GarbageCollector, char const*, char const*, v8::GCCallbackFlags)
 4: v8::internal::Heap::CollectAllGarbage(int, char const*, v8::GCCallbackFlags)
 5: v8::internal::Heap::AdvanceIdleIncrementalMarking(long)
 6: v8::internal::Heap::IdleNotification(int)
 7: ??
 8: zend_objects_store_del_ref_by_handle_ex
 9: zend_objects_store_del_ref
10: _zval_ptr_dtor
11: ??
12: zend_hash_reverse_apply
13: ??
14: ??
15: php_request_shutdown
16: ??
17: ??
18: __libc_start_main
19: ??
Trace/breakpoint trap