[clang] [Clang](NFC) Add coverage for VTable debug info (PR #151818)

[Jeremy Morse via cfe-commits]

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@@ -0,0 +1,93 @@
+// The debug info of vtable is attached conditionally to whether
+// - Member functions are inlined or not
+// - Definition of destructor is visible or not
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jmorse wrote:

Would you be able to give a sentence summarising what the CHECK-lines below are seeking, i.e. "expect to see the variable attached to...", as it's hard to immediately work out what's being checked. Something like your leading comment on vtable-template-instantiation.cpp. This'll help a lot if we come to refactoring the representation in metadata.

https://github.com/llvm/llvm-project/pull/151818