Fix requested for C++ compatibility

I'd like to thank whoever fixed Zend/zend_interfaces.h in RC2 so that it avoids a "duplicate symbol" link error when building PHP with a C++ compiler. However, a similar issue was introduced in RC2 in Zend/zend_exceptions.h: ZEND_API void (*zend_throw_exception_hook)(zval *ex TSRMLS_DC); It would be great if someone could prepend "extern" to the above line. Thanks, - Mark