PHASE II : Support for python ibm_db driver on z/OS using z ODBC driver

The requirement is to offer connectivity to Db2 on z/OS natively by using the z/OS ODBC driver.

The python driver has been enhanced to successfully compile on the z/OS platform, and basic validation and regression suite validation has been done. While running regression suite, there has been certain failures that are observed and are currently under investigation with z ODBC dev team, All other cases that required either code change or test change has been done in ibm_db layer.

This request is for fixing the problems identified for Phase II implementation by z/OS ODBC Dev team.

The scenarios to address are:
1. SQLNumResultCols() failed:

DB2 FOR OS/390}{ODBC DRIVER} SQLSTATE=HY010 ERRLOC=7:7:3ERRORLOC=7:7:3 in SQLNumResultCols()

Problem is related to SQLExecDirect and SQLFreeHandle(), when free stmt handle 1, stmt handle 2's information

2. When it is "" as input,

For SQL_CHAR/VARCHAR:

SQLCODE=320, SQLSTATE=22001, it is a ODBC issue.Error:

Exception: Statement Execute Failed: {DB2 FOR OS/390}{ODBC DRIVER}{DSN12015}  DSNT408I SQLCODE = -302, ERROR:  THE VALUE OF INPUT VARIABLE OR PARAMETER                NUMBER 8 IS INVALID OR TOO LARGE FOR THE TAR

GET COLUMN OR THE TARGET            VALUE                                                                  DSNT418I SQLSTATE   = 22001 SQLSTATE RETURN CODE                                DSNT415I SQLERRP    = DS

NXRIHB SQL PROCEDURE DETECTING ERROR                    DSNT416I SQLERRD    = -320  0  0  -1  0  0 SQL DIAGNOSTIC INFORMATION           DSNT416I SQLERRD    = X'FFFFFEC0'  X'00000000'  X'00000000'  X'FFFFFFFF'

              X'00000000'  X'00000000' SQL DIAGNOSTIC INFORMATION                     ERRLOC=5:10:2 SQLCODE=-302