[clang] [StaticAnalyzer] Fix non decimal macro values in tryExpandAsInteger (PR #168632)

[Colin Kinloch via cfe-commits]

================
@@ -142,19 +142,25 @@ std::optional<int> tryExpandAsInteger(StringRef Macro, const Preprocessor &PP) {
   if (InvalidSpelling)
     return std::nullopt;
 
-  llvm::APInt IntValue;
+  llvm::APSInt IntValue(0, true);
   constexpr unsigned AutoSenseRadix = 0;
-  if (ValueStr.getAsInteger(AutoSenseRadix, IntValue))
+  if (ValueStr.getAsInteger(AutoSenseRadix,
+                            static_cast<llvm::APInt &>(IntValue)))
----------------
ColinKinloch wrote:

`StringRef::getAsInteger` has two definitions, in one the `Result` argument is  a `APInt &`, the other is a template. Without the `static_cast` the compilation fails with:
```
llvm-project/llvm/include/llvm/ADT/StringRef.h:485:13: error: invalid ‘static_cast’ from type ‘llvm::APSInt’ to type ‘long long unsigned int’
```

https://github.com/llvm/llvm-project/pull/168632