Fix #14287 Crash in valueFlowSymbolic() with initializer list (danmar#7976)

Co-authored-by: chrchr-github <noreply@github.com>

Author: chrchr-github

lib/token.cpp

@@ -2459,7 +2459,7 @@ std::pair<const Token*, const Token*> Token::typeDecl(const Token* tok, bool poi
                     typeBeg = previousBeforeAstLeftmostLeaf(tok2);
                     typeEnd = tok2;
                 }
-                if (typeBeg)
+                if (typeBeg && typeBeg != typeEnd)
                     result = { typeBeg->next(), typeEnd }; // handle smart pointers/iterators first
             }
             if (astIsRangeBasedForDecl(var->nameToken()) && astIsContainer(var->nameToken()->astParent()->astOperand2())) { // range-based for

test/testvalueflow.cpp

@@ -7990,6 +7990,12 @@ class TestValueFlow : public TestFixture {
                "};\n"
                "U<S*> u;\n";
         (void)valueOfTok(code, "new");
+
+        code = "void f() {\n" // #14287
+               "    auto a = { \"1\" };\n"
+               "    auto b = a;\n"
+               "}\n";
+        (void)valueOfTok(code, "b");
     }
 
     void valueFlowHang() {