[analyzer] Fix assertion on casting SVal to NonLoc inside the IteratorRange checker

[steakhal]

Summary

The checker assumed that it could safely cast an SVal to Nonloc.
This surfaced because, with std::ranges, we can unintentionally match
on other APIs as well, thus increasing the likelihood of violating
checker assumptions about the context it's invoked.
https://godbolt.org/z/13vEb3K76

See the discourse post on CallDescriptions and std::ranges here.
https://discourse.llvm.org/t/calldescriptions-should-not-skip-the-ranges-part-in-std-names-when-matching/73076

Fixes https://github.com/llvm/llvm-project/issues/65009

[donat.nagy]

LGTM. I'm not familiar with the Iterator checker family, but this is a very straightforward change.

[steakhal]

In D158968#4620721, @donat.nagy wrote:

LGTM. I'm not familiar with the Iterator checker family, but this is a very straightforward change.

Thanks for the review!
Well, it's an Ericsson checker ;)

clang/lib/StaticAnalyzer/Checkers/IteratorRangeChecker.cpp

void IteratorRangeChecker::verifyRandomIncrOrDecr(CheckerContext &C,
                                                   SVal LHS, SVal RHS) const {
   auto State = C.getState();
 
   auto Value = RHS;
   if (auto ValAsLoc = RHS.getAs<Loc>()) {
     Value = State->getRawSVal(*ValAsLoc);
   }
 
-  if (Value.isUnknownOrUndef())
+  if (Value.isUnknownOrUndef() || !isa<NonLoc>(Value))
     return;
 
   // Incremention or decremention by 0 is never a bug.
   if (isZero(State, Value.castAs<NonLoc>()))
     return;
 
   // The result may be the past-end iterator of the container, but any other
   // out of range position is undefined behaviour

clang/test/Analysis/iterator-range.cpp

 }
 
 int uninit_var(int n) {
   int uninit; // expected-note{{'uninit' declared without an initial value}}
   return n - uninit; // no-crash
   // expected-warning@-1 {{The right operand of '-' is a garbage value}}
   // expected-note@-2 {{The right operand of '-' is a garbage value}}
 }
+
+namespace std {
+namespace ranges {
+  template <class InOutIter, class Sentinel>
+  InOutIter next(InOutIter, Sentinel);
+} // namespace ranges
+} // namespace std
+
+void gh65009__no_crash_on_ranges_next(int **begin, int **end) {
+  (void)std::ranges::next(begin, end); // no-crash
+}