[clang] [Clang][Sema] Fix lambdas mistakenly inheriting InImmediateFunctionContext (PR #232458)

[Corentin Jabot via cfe-commits]

cor3ntin wrote:

I think you are close. 

Try something like 
```
if (isLambdaMethod(FD) && !isLambdaCallOperator(FD))
      Current.InImmediateFunctionContext = FD->isConsteval() ||
                                           Parent.isConstantEvaluated() ||
                                           Parent.isImmediateFunctionContext();```

https://github.com/llvm/llvm-project/pull/232458