Fix FN constVariableReference (#4949)

Author: chrchr-github

lib/checkother.cpp

@@ -1471,6 +1471,8 @@ void CheckOther::checkConstVariable()
                 if (tok->isUnaryOp("&") && Token::Match(tok, "& %varid%", var->declarationId())) {
                     const Token* opTok = tok->astParent();
                     int argn = -1;
+                    if (opTok && opTok->isUnaryOp("!"))
+                        continue;
                     if (opTok && (opTok->isComparisonOp() || opTok->isAssignmentOp() || opTok->isCalculation())) {
                         if (opTok->isComparisonOp() || opTok->isCalculation()) {
                             if (opTok->astOperand1() != tok)

test/testother.cpp

@@ -3502,7 +3502,7 @@ class TestOther : public TestFixture {
               "    int& r = i;\n"
               "    if (!&r) {}\n"
               "}\n");
-        TODO_ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'r' can be declared as reference to const\n", "", errout.str()); // don't crash
+        ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'r' can be declared as reference to const\n", errout.str()); // don't crash
 
         check("class C;\n" // #11646
               "void g(const C* const p);\n"