[clang] [analyzer] Fix crash in PaddingChecker on dependent field types (PR #232986)

[Balázs Benics via cfe-commits]

================
@@ -0,0 +1,7 @@
+// RUN: %clang_analyze_cc1 -std=c++20 -analyzer-checker=optin.performance -verify %s
----------------
steakhal wrote:

I presume the checker already have at least one test file. I think we should squeeze this into one of those tests and suffix the line with `// no-crash` to illustrate that this used to crash.

https://github.com/llvm/llvm-project/pull/232986