Fix #13515 Crash in getParentLifetime() (danmar#7171)

Author: chrchr-github

lib/astutils.cpp

@@ -675,6 +675,8 @@ const Token* getParentLifetime(const Token* tok, const Library& library)
     // If any of the submembers are borrowed types then stop
     if (std::any_of(it.base() - 1, members.cend() - 1, [&](const Token* tok2) {
         const Token* obj = getParentLifetimeObject(tok2);
+        if (!obj)
+            return false;
         const Variable* var = obj->variable();
         // Check for arrays first since astIsPointer will return true, but an array is not a borrowed type
         if (var && var->isArray())

test/testvalueflow.cpp

@@ -7350,6 +7350,11 @@ class TestValueFlow : public TestFixture {
                "    int j;\n"
                "};\n";
         (void)valueOfTok(code, "B");
+
+        code = "void f(int& r) {\n" // #13515
+               "    [0].p = &r;\n"
+               "}\n";
+        (void)valueOfTok(code, "=");
     }
 
     void valueFlowCrash() {