Fix GUC's reports of assign_hook failure to always include the parameter value we failed to assign, even in "can't happen" cases.  Motivated by wondering what's going on in a recent trouble report where "failed to commit" did happen.
Fix GUC's reports of assign_hook failure to always include the parameter value
we failed to assign, even in "can't happen" cases.  Motivated by wondering
what's going on in a recent trouble report where "failed to commit" did
happen.

Chibin/gpdb,ashwinstar/gpdb,edespino/gpdb,zaksoup/gpdb,lisakowen/gpdb,xinzweb/gpdb,xinzweb/gpdb,chrishajas/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,ahachete/gpdb,greenplum-db/gpdb,Chibin/gpdb,chrishajas/gpdb,ashwinstar/gpdb,Quikling/gpdb,50wu/gpdb,lintzc/gpdb,ahachete/gpdb,zaksoup/gpdb,50wu/gpdb,janebeckman/gpdb,jmcatamney/gpdb,kaknikhil/gpdb,lintzc/gpdb,rvs/gpdb,CraigHarris/gpdb,ahachete/gpdb,rvs/gpdb,lisakowen/gpdb,cjcjameson/gpdb,Quikling/gpdb,royc1/gpdb,0x0FFF/gpdb,Chibin/gpdb,CraigHarris/gpdb,xinzweb/gpdb,edespino/gpdb,kaknikhil/gpdb,rvs/gpdb,xinzweb/gpdb,rvs/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,xinzweb/gpdb,50wu/gpdb,chrishajas/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,0x0FFF/gpdb,royc1/gpdb,CraigHarris/gpdb,rvs/gpdb,lisakowen/gpdb,ashwinstar/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,rvs/gpdb,cjcjameson/gpdb,adam8157/gpdb,royc1/gpdb,adam8157/gpdb,edespino/gpdb,royc1/gpdb,Quikling/gpdb,xuegang/gpdb,kaknikhil/gpdb,janebeckman/gpdb,xuegang/gpdb,lisakowen/gpdb,lintzc/gpdb,rvs/gpdb,zaksoup/gpdb,jmcatamney/gpdb,xinzweb/gpdb,ahachete/gpdb,lintzc/gpdb,edespino/gpdb,0x0FFF/gpdb,Quikling/gpdb,0x0FFF/gpdb,ashwinstar/gpdb,CraigHarris/gpdb,chrishajas/gpdb,janebeckman/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,ahachete/gpdb,jmcatamney/gpdb,zaksoup/gpdb,50wu/gpdb,zaksoup/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,zaksoup/gpdb,50wu/gpdb,50wu/gpdb,Quikling/gpdb,edespino/gpdb,lisakowen/gpdb,lintzc/gpdb,adam8157/gpdb,xuegang/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,rvs/gpdb,Chibin/gpdb,xuegang/gpdb,adam8157/gpdb,adam8157/gpdb,xuegang/gpdb,rvs/gpdb,kaknikhil/gpdb,xuegang/gpdb,janebeckman/gpdb,ahachete/gpdb,Chibin/gpdb,edespino/gpdb,jmcatamney/gpdb,ahachete/gpdb,cjcjameson/gpdb,chrishajas/gpdb,kaknikhil/gpdb,Quikling/gpdb,ahachete/gpdb,ashwinstar/gpdb,janebeckman/gpdb,greenplum-db/gpdb,edespino/gpdb,cjcjameson/gpdb,lisakowen/gpdb,0x0FFF/gpdb,janebeckman/gpdb,kaknikhil/gpdb,zaksoup/gpdb,CraigHarris/gpdb,cjcjameson/gpdb,lintzc/gpdb,cjcjameson/gpdb,0x0FFF/gpdb,royc1/gpdb,xinzweb/gpdb,chrishajas/gpdb,Quikling/gpdb,royc1/gpdb,lisakowen/gpdb,xinzweb/gpdb,Chibin/gpdb,lintzc/gpdb,janebeckman/gpdb,lisakowen/gpdb,Chibin/gpdb,janebeckman/gpdb,chrishajas/gpdb,greenplum-db/gpdb,yuanzhao/gpdb,adam8157/gpdb,rvs/gpdb,50wu/gpdb,Quikling/gpdb,edespino/gpdb,zaksoup/gpdb,adam8157/gpdb,lintzc/gpdb,greenplum-db/gpdb,CraigHarris/gpdb,50wu/gpdb,ashwinstar/gpdb,lintzc/gpdb,royc1/gpdb,greenplum-db/gpdb,0x0FFF/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,kaknikhil/gpdb,ashwinstar/gpdb,royc1/gpdb,CraigHarris/gpdb,Chibin/gpdb,CraigHarris/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,Quikling/gpdb,greenplum-db/gpdb,0x0FFF/gpdb,chrishajas/gpdb,xuegang/gpdb,edespino/gpdb,Chibin/gpdb,xuegang/gpdb,adam8157/gpdb,janebeckman/gpdb,jmcatamney/gpdb,Quikling/gpdb,yuanzhao/gpdb,Chibin/gpdb,edespino/gpdb,yuanzhao/gpdb,janebeckman/gpdb,jmcatamney/gpdb,xuegang/gpdb