[clang] [StaticAnalyzer] Fix tryExpandAsInteger's failures on PCH macros (PR #142722)

[Balazs Benics via cfe-commits]

steakhal wrote:

FYI the CI checks are red, I don't think its related to this PR.
It had this line:
```
2025-06-05T08:01:02.4802924Z PASS: Clang :: Analysis/pch_macro.cpp (1263 of 21496)
```
So we should be good to merge, any time you want.

https://github.com/llvm/llvm-project/pull/142722