[clang] [AST][RecoveryExpr] Fix a crash on c89/c90 invalid InitListExpr (#88008) (PR #88014)

[Aaron Ballman via cfe-commits]

================
@@ -423,6 +423,8 @@ Bug Fixes in This Version
 - Fixed a regression in CTAD that a friend declaration that befriends itself may cause
   incorrect constraint substitution. (#GH86769).
 
+- Fixed an assertion failure on invalid InitListExpr in C90 mode (#GH88008).
----------------
AaronBallman wrote:

```suggestion
- Fixed an assertion failure on invalid InitListExpr in C89 mode (#GH88008).
```

https://github.com/llvm/llvm-project/pull/88014