Partial fix for #14810 FN constVariablePointer (cbegin() called on container) (#8619)

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

Author: chrchr-github

lib/library.cpp

@@ -1781,6 +1781,8 @@ bool Library::isFunctionConst(const Token *ftok) const
             const Yield yield = astContainerYield(ftok->astParent()->astOperand1(), *this);
             if (yield == Yield::EMPTY || yield == Yield::SIZE || yield == Yield::BUFFER_NT)
                 return true;
+            if ((yield == Yield::START_ITERATOR || yield == Yield::END_ITERATOR) && ftok->str()[0] == 'c')
+                return true;
         }
         return false;
     }

test/testother.cpp

@@ -4867,6 +4867,11 @@ class TestOther : public TestFixture {
         ASSERT_EQUALS("[test.cpp:1:12]: (style) Parameter 'p' can be declared as pointer to const [constParameterPointer]\n"
                       "[test.cpp:1:20]: (style) Parameter 'q' can be declared as pointer to const [constParameterPointer]\n",
                       errout_str());
+
+        check("int f(std::vector<int>* p) {\n" // #14810
+              "    return *p->cbegin();\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:1:25]: (style) Parameter 'p' can be declared as pointer to const [constParameterPointer]\n", errout_str());
     }
 
     void constArray() {