Fix #14287 Crash in valueFlowSymbolic() with initializer list

Author: web-flow

lib/valueflow.cpp

@@ -1968,6 +1968,8 @@ static const Token* skipCVRefs(const Token* tok, const Token* endTok)
 
 static bool isNotEqual(std::pair<const Token*, const Token*> x, std::pair<const Token*, const Token*> y)
 {
+    if (x == y)
+        return false;
     const Token* start1 = x.first;
     const Token* start2 = y.first;
     if (start1 == nullptr || start2 == nullptr)

test/testvalueflow.cpp

@@ -7990,6 +7990,12 @@ class TestValueFlow : public TestFixture {
                "};\n"
                "U<S*> u;\n";
         (void)valueOfTok(code, "new");
+
+        code = "void f() {\n"
+               "    auto a = { \"1\" };\n"
+               "    auto b = a;\n"
+              "}\n";
+        (void)valueOfTok(code, "b");
     }
 
     void valueFlowHang() {