[stable] Fix Issue 24139 - 'this' corruption in extern(C++) dtor when destructing via TypeInfo_Struct

[kinke]

For the TypeInfo_Struct.xdtor field, the linkage of the aggregate itself plays no role; it's the linkage of the destructor that matters.

A real-life example for this is DMD's own OutBuffer.

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	24139	major	'this' corruption in extern(C++) dtor when destructing via TypeInfo_Struct

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "stable + dmd#15598"