[analyzer] Assume 'new' never returns NULL if it could throw an exception.
This is actually required by the C++ standard in
If an allocation function declared with a non-throwing exception-specification fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall indicate failure only by throwing an exception of a type that would match a handler of type std::bad_alloc.
We don't bother checking for the specific exception type, but just go off
the operator new prototype. This should help with a certain class of lazy
initalization false positives.