The skip message must start with the word 'skip', otherwise the test will not be skipped.

*Before:*
Running selected tests.
TEST 1/1 [ext/com_dotnet/tests/bug79332.phpt]
========DIFF========
001+ Fatal error: Uncaught Error: Class 'COMPersistHelper' not found in /srv/php/ext/com_dotnet/tests/bug79332.php:2
001- A com_exception has been thrown
002+ Stack trace:
003+ #0 {main}
004+   thrown in /srv/php/ext/com_dotnet/tests/bug79332.php on line 2
========DONE========
FAIL Bug #79332 (php_istreams are never freed) [ext/com_dotnet/tests/bug79332.phpt]

*After:*
Running selected tests.
SKIP Bug #79332 (php_istreams are never freed) [ext/com_dotnet/tests/bug79332.phpt] reason: com_dotnet extension not available

We have to free the `ansiname`s, regardless of whether they have been
put into the hashtable or not.

Since bug79299.phpt already shows the leak when run with a leak
checker, there is no need for another regression test.

Releasing the `com_dotnet_istream_wrapper` in `istream_destructor()` is
pointless, since `istream_destructor()` is only called when the
resource is going to be released.  This recursion is not a real issue,
though, since the resource is never exposed to userland, and has at
most refcount 1, so due to well defined unsigned integer underflow, it
never is released twice.  However, returning early in this case causes
a memory leak which needs to be fixed.

`lastid` has to retain its value during the traversal, so we move it to
an outer scope.

Patch contributed by Litiano Moura.

If the `VT_ARRAY` is empty, i.e. its upperbound is less than its lower
bound, we must not call `php_com_safearray_get_elem()`, because that
function throws in this case.

`-2200000000` can't be converted to integer on x86, so the constructor
call would fail.

Because a `HRESULT` is a `LONG`[1], no special treatment is required on
x86 platforms to get appropriate values.  On x64 platforms we prefer
positive values, what we could accomplish by casting the `HRESULT`
value to `ULONG` and then to `zend_long`, but since the current
behavior is correct and the performance improvement is negligible, we
defer that to master.

[1] <https://docs.microsoft.com/en-us/windows/win32/winprog/windows-data-types#hresult>

Saving under the given `filename` may also work, but since
`::LoadFromFile` uses the `fullpath` we follow suit.

* PHP-7.2:
  Fix #78694: Appending to a variant array causes segfault

`write_dimension` object handlers have to be able to handle `NULL`
`offset`s; for now we simply throw an exception instead of following
the `NULL` pointer.