[clang][win] Define vector deleting dtor body for declared-only dtor if needed (#185653)

Currently vector deleting destructor body emission is triggered if new[]
is called for the type and if the destructor or the whole class is
marked with attribute dllexport. The problem is that it is not emitted
if new[] is called, destructor is not exported and it is only declared
in the TU and defined in another. That makes vector deleting destructor
body missing which leads to runtime failures in delete[].

This change forces vector deleting destructor body emission if new[] is
called even if the destructor is only declared but not defined. Doing
that replicates MSVC behavior and fixes runtime issues. Since vector
deleting destructors have weak linkage, it should be safe to do so.

Fixes https://github.com/llvm/llvm-project/issues/183255

AI usage: Claude was used to create LIT test cases which then were
reviewed and reworked by me.