perf: skip instantiation of testReturn and functionReturnType for non-callable statements
perf: skip instantiation of testReturn and functionReturnType for non-callable statements

testReturn and functionReturnType are used in Callable functions only, so avoid overhead for prepared statements.

underyx/pgjdbc,jorsol/pgjdbc,golovnin/pgjdbc,whitingjr/pgjdbc,panchenko/pgjdbc,pgjdbc/pgjdbc,marschall/pgjdbc,davecramer/pgjdbc,AlexElin/pgjdbc,bocap/pgjdbc,underyx/pgjdbc,underyx/pgjdbc,amozhenin/pgjdbc,lordnelson/pgjdbc,whitingjr/pgjdbc,sehrope/pgjdbc,rjmac/pgjdbc,jorsol/pgjdbc,rjmac/pgjdbc,amozhenin/pgjdbc,sehrope/pgjdbc,zemian/pgjdbc,zapov/pgjdbc,panchenko/pgjdbc,sehrope/pgjdbc,lordnelson/pgjdbc,marschall/pgjdbc,Gordiychuk/pgjdbc,jorsol/pgjdbc,phillipross/pgjdbc,AlexElin/pgjdbc,golovnin/pgjdbc,jamesthomp/pgjdbc,jkutner/pgjdbc,amozhenin/pgjdbc,zemian/pgjdbc,pgjdbc/pgjdbc,golovnin/pgjdbc,marschall/pgjdbc,phillipross/pgjdbc,sehrope/pgjdbc,jkutner/pgjdbc,jamesthomp/pgjdbc,zemian/pgjdbc,davecramer/pgjdbc,Gordiychuk/pgjdbc,zapov/pgjdbc,pgjdbc/pgjdbc,Gordiychuk/pgjdbc,zapov/pgjdbc,marschall/pgjdbc,pgjdbc/pgjdbc,jorsol/pgjdbc,jkutner/pgjdbc,panchenko/pgjdbc,AlexElin/pgjdbc,bocap/pgjdbc,jamesthomp/pgjdbc,davecramer/pgjdbc,phillipross/pgjdbc,rjmac/pgjdbc,lordnelson/pgjdbc,whitingjr/pgjdbc,davecramer/pgjdbc,bocap/pgjdbc