SHOWPLAN related changes Reworked the fix for bug 1392522 - mxosrvr core dumped doing showplan (with N.E. enabled), plus other related code changes. 1) The native code (also known as native expression), if generated, is stored in the expression's constant area. SHOWPLAN will dump the native code in the assembly format. The display can be disabled by CQD PCODE_NE_IN_SHOWPLAN to "OFF". It is "ON" by default. This part had been reviewed by Jim Capps and Mike Hanlon. 2) Add several SHOWPLAN statements in core/TEST019 without logging the output. This is to ensure no core generated when getting executor operator (TDBs) info via SHOWPLAN. 3) A temporary fix to ComTdbHbaseAccess::displayRowId(). The current way of retrieving begin or end row IDs from the HbaseScanRows for SHOWPLAN does not match with the way those row IDs are generated (see HbaseAccess::genListsOfRows), causing core dumps in some cases.