[NFC][Clang] Fix static analyzer concern (llvm#88179)

Fix static analyzer concerns about dereferencing
null values.

Author: elizabethandrews

clang/lib/AST/Interp/InterpState.h

@@ -89,7 +89,11 @@ class InterpState final : public State, public SourceMapper {
 
   /// Delegates source mapping to the mapper.
   SourceInfo getSource(const Function *F, CodePtr PC) const override {
-    return M ? M->getSource(F, PC) : F->getSource(PC);
+    if (M)
+      return M->getSource(F, PC);
+
+    assert(F && "Function cannot be null");
+    return F->getSource(PC);
   }
 
   Context &getContext() const { return Ctx; }

clang/lib/Sema/SemaAPINotes.cpp

@@ -463,6 +463,8 @@ static void ProcessAPINotes(Sema &S, FunctionOrMethod AnyFunc,
     D = MD;
   }
 
+  assert((FD || MD) && "Expecting Function or ObjCMethod");
+
   // Nullability of return type.
   if (Info.NullabilityAudited)
     applyNullability(S, D, Info.getReturnTypeInfo(), Metadata);