Fixed some cppcheck warnings about methods that can be static/const

lib/checkautovariables.cpp

@@ -317,7 +317,7 @@ void CheckAutoVariables::errorUselessAssignmentPtrArg(const Token *tok)
 //---------------------------------------------------------------------------
 
 // return temporary?
-bool CheckAutoVariables::returnTemporary(const Token *tok) const
+bool CheckAutoVariables::returnTemporary(const Token *tok)
 {
     bool func = false;     // Might it be a function call?
     bool retref = false;   // is there such a function that returns a reference?

lib/checkautovariables.h

@@ -79,7 +79,7 @@ private:
      * @param tok pointing at the "return" token
      * @return true if a temporary object is returned
      */
-    bool returnTemporary(const Token *tok) const;
+    static bool returnTemporary(const Token *tok);
 
     void errorReturnAddressToAutoVariable(const Token *tok);
     void errorReturnPointerToLocalArray(const Token *tok);

lib/checkobsolescentfunctions.h

@@ -62,7 +62,7 @@ private:
     static std::map<std::string, std::string> _obsoleteC99Functions;
 
     /** init obsolete functions list ' */
-    void initObsoleteFunctions() {
+    static void initObsoleteFunctions() {
         // Obsolete posix functions, which messages suggest only one alternative and doesn't contain additional information.
         const struct {
             const char* bad;

lib/symboldatabase.cpp

@@ -1301,7 +1301,7 @@ SymbolDatabase::~SymbolDatabase()
     }
 }
 
-bool SymbolDatabase::isFunction(const Token *tok, const Scope* outerScope, const Token **funcStart, const Token **argStart)
+bool SymbolDatabase::isFunction(const Token *tok, const Scope* outerScope, const Token **funcStart, const Token **argStart) const
 {
     if (tok->varId())
         return false;

lib/symboldatabase.h

@@ -1019,7 +1019,7 @@ private:
     Function *addGlobalFunctionDecl(Scope*& scope, const Token* tok, const Token *argStart, const Token* funcStart);
     Function *addGlobalFunction(Scope*& scope, const Token*& tok, const Token *argStart, const Token* funcStart);
     void addNewFunction(Scope **info, const Token **tok);
-    bool isFunction(const Token *tok, const Scope* outerScope, const Token **funcStart, const Token **argStart);
+    bool isFunction(const Token *tok, const Scope* outerScope, const Token **funcStart, const Token **argStart) const;
     const Type *findTypeInNested(const Token *tok, const Scope *startScope) const;
     const Scope *findNamespace(const Token * tok, const Scope * scope) const;
     Function *findFunctionInScope(const Token *func, const Scope *ns);