Fix Issue 19871 - Copy constructor rejects valid code if default construction is disabled

[RazvanN7]

The initial idea was that when the compiler searches for copy constructors it should stop when it has found one, however, it should also check if the user has defined an rvalue normal constructor. The patch makes it so that the search for copy constructors does not stop when a copy constructor was found.

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	19871	regression	Copy constructor rejects valid code if default construction is disabled

Testing this PR locally

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

dub fetch digger
dub run digger -- build "stable + dmd#9792"