Coverity scan reported new defects related to code generator

*** CID 1143179:  Null pointer dereferences  (FORWARD_NULL)
/home/vamosax/build/CE/platform/build-master-2021-10-18_10-01-35/ecl/hql/hqllex.cpp: 7520 in eclyyrestart(_IO_FILE *, void *)()
7514         void eclyyrestart  (FILE * input_file , yyscan_t yyscanner)
7515     {
7516         struct yyguts_t * yyg = (struct yyguts_t*)yyscanner;
7517
7518            if ( ! YY_CURRENT_BUFFER ){
7519             eclyyensure_buffer_stack (yyscanner);
>>>     CID 1143179:  Null pointer dereferences  (FORWARD_NULL)
>>>     Dereferencing null pointer "yyg->yy_buffer_stack".
7520                    YY_CURRENT_BUFFER_LVALUE =
7521                 eclyy_create_buffer(yyin,YY_BUF_SIZE ,yyscanner);
7522            }
7523
7524            eclyy_init_buffer(YY_CURRENT_BUFFER,input_file ,yyscanner);
7525            eclyy_load_buffer_state(yyscanner );

________________________________________________________________________________________________________
*** CID 1142620:  Null pointer dereferences  (FORWARD_NULL)
/home/vamosax/build/CE/platform/build-master-2021-10-18_10-01-35/ecl/hql/hqllex.cpp: 7553 in eclyy_switch_to_buffer(yy_buffer_state *, void *)()
7547                    /* Flush out information for old buffer. */
7548                    *yyg->yy_c_buf_p = yyg->yy_hold_char;
7549                    YY_CURRENT_BUFFER_LVALUE->yy_buf_pos = yyg->yy_c_buf_p;
7550                    YY_CURRENT_BUFFER_LVALUE->yy_n_chars = yyg->yy_n_chars;
7551                    }
7552
>>>     CID 1142620:  Null pointer dereferences  (FORWARD_NULL)
>>>     Dereferencing null pointer "yyg->yy_buffer_stack".
7553            YY_CURRENT_BUFFER_LVALUE = new_buffer;
7554            eclyy_load_buffer_state(yyscanner );
7555
7556            /* We don't actually know whether we did this switch during
7557             * EOF (eclyywrap()) processing, but the only time this flag
7558             * is looked at is after eclyywrap() is called, so it's safe

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*** CID 1142402:  Null pointer dereferences  (FORWARD_NULL)
/home/vamosax/build/CE/platform/build-master-2021-10-18_10-01-35/ecl/hql/hqllex.cpp: 7706 in eclyypush_buffer_state(yy_buffer_state *, void *)()
7700                    YY_CURRENT_BUFFER_LVALUE->yy_n_chars = yyg->yy_n_chars;
7701                    }
7702
7703            /* Only push if top exists. Otherwise, replace top. */
7704            if (YY_CURRENT_BUFFER)
7705                    yyg->yy_buffer_stack_top++;
>>>     CID 1142402:  Null pointer dereferences  (FORWARD_NULL)
>>>     Dereferencing null pointer "yyg->yy_buffer_stack".
7706            YY_CURRENT_BUFFER_LVALUE = new_buffer;
7707
7708            /* copied from eclyy_switch_to_buffer. */
7709            eclyy_load_buffer_state(yyscanner );
7710            yyg->yy_did_buffer_switch_on_eof = 1;
7711     }