Eliminate an unnecessary use of ASTContext::getOrCreateCanonicalGenericEnvironment().
Eliminate an unnecessary use of ASTContext::getOrCreateCanonicalGenericEnvironment().

GenericSignature::createGenericEnvironment() is a better API for this.

return/swift,alblue/swift,apple/swift,huonw/swift,tkremenek/swift,hooman/swift,alblue/swift,roambotics/swift,danielmartin/swift,airspeedswift/swift,glessard/swift,devincoughlin/swift,huonw/swift,jtbandes/swift,frootloops/swift,airspeedswift/swift,karwa/swift,uasys/swift,Jnosh/swift,swiftix/swift,tjw/swift,shahmishal/swift,tjw/swift,airspeedswift/swift,JGiola/swift,nathawes/swift,rudkx/swift,gregomni/swift,Jnosh/swift,hooman/swift,tjw/swift,atrick/swift,milseman/swift,jmgc/swift,CodaFi/swift,zisko/swift,parkera/swift,amraboelela/swift,karwa/swift,milseman/swift,danielmartin/swift,djwbrown/swift,allevato/swift,uasys/swift,airspeedswift/swift,sschiau/swift,stephentyrone/swift,xwu/swift,deyton/swift,harlanhaskins/swift,JGiola/swift,xedin/swift,gribozavr/swift,atrick/swift,calebd/swift,allevato/swift,glessard/swift,roambotics/swift,jtbandes/swift,devincoughlin/swift,practicalswift/swift,benlangmuir/swift,xwu/swift,danielmartin/swift,CodaFi/swift,gregomni/swift,shahmishal/swift,austinzheng/swift,jmgc/swift,djwbrown/swift,stephentyrone/swift,frootloops/swift,deyton/swift,karwa/swift,atrick/swift,brentdax/swift,xwu/swift,brentdax/swift,atrick/swift,tjw/swift,nathawes/swift,swiftix/swift,alblue/swift,jckarter/swift,parkera/swift,milseman/swift,ahoppen/swift,airspeedswift/swift,frootloops/swift,tkremenek/swift,glessard/swift,uasys/swift,jtbandes/swift,hooman/swift,brentdax/swift,aschwaighofer/swift,deyton/swift,shajrawi/swift,CodaFi/swift,jckarter/swift,jckarter/swift,natecook1000/swift,CodaFi/swift,karwa/swift,xedin/swift,jtbandes/swift,shajrawi/swift,zisko/swift,practicalswift/swift,roambotics/swift,practicalswift/swift,shahmishal/swift,CodaFi/swift,aschwaighofer/swift,Jnosh/swift,milseman/swift,stephentyrone/swift,return/swift,xedin/swift,alblue/swift,gregomni/swift,frootloops/swift,danielmartin/swift,shajrawi/swift,tjw/swift,milseman/swift,sschiau/swift,OscarSwanros/swift,deyton/swift,ahoppen/swift,uasys/swift,natecook1000/swift,practicalswift/swift,return/swift,felix91gr/swift,shahmishal/swift,apple/swift,devincoughlin/swift,gribozavr/swift,atrick/swift,benlangmuir/swift,jckarter/swift,harlanhaskins/swift,sschiau/swift,glessard/swift,OscarSwanros/swift,airspeedswift/swift,jopamer/swift,devincoughlin/swift,ahoppen/swift,amraboelela/swift,harlanhaskins/swift,huonw/swift,amraboelela/swift,austinzheng/swift,xedin/swift,danielmartin/swift,zisko/swift,nathawes/swift,allevato/swift,airspeedswift/swift,allevato/swift,harlanhaskins/swift,gribozavr/swift,ahoppen/swift,zisko/swift,rudkx/swift,amraboelela/swift,calebd/swift,hughbe/swift,jopamer/swift,natecook1000/swift,devincoughlin/swift,tkremenek/swift,allevato/swift,xwu/swift,hughbe/swift,benlangmuir/swift,JGiola/swift,swiftix/swift,hooman/swift,xwu/swift,hooman/swift,nathawes/swift,calebd/swift,allevato/swift,swiftix/swift,gribozavr/swift,jmgc/swift,jmgc/swift,djwbrown/swift,karwa/swift,felix91gr/swift,karwa/swift,return/swift,hughbe/swift,shajrawi/swift,practicalswift/swift,xedin/swift,atrick/swift,alblue/swift,djwbrown/swift,practicalswift/swift,Jnosh/swift,uasys/swift,CodaFi/swift,alblue/swift,jtbandes/swift,djwbrown/swift,shajrawi/swift,xwu/swift,jtbandes/swift,jopamer/swift,zisko/swift,jopamer/swift,djwbrown/swift,devincoughlin/swift,practicalswift/swift,parkera/swift,tkremenek/swift,benlangmuir/swift,calebd/swift,gribozavr/swift,djwbrown/swift,xedin/swift,OscarSwanros/swift,hughbe/swift,parkera/swift,shajrawi/swift,austinzheng/swift,frootloops/swift,aschwaighofer/swift,austinzheng/swift,jopamer/swift,aschwaighofer/swift,zisko/swift,gregomni/swift,jckarter/swift,huonw/swift,xedin/swift,shahmishal/swift,lorentey/swift,Jnosh/swift,roambotics/swift,swiftix/swift,shahmishal/swift,jopamer/swift,tkremenek/swift,aschwaighofer/swift,karwa/swift,xedin/swift,glessard/swift,swiftix/swift,felix91gr/swift,rudkx/swift,return/swift,shajrawi/swift,felix91gr/swift,parkera/swift,roambotics/swift,aschwaighofer/swift,tjw/swift,harlanhaskins/swift,felix91gr/swift,return/swift,jmgc/swift,nathawes/swift,uasys/swift,lorentey/swift,harlanhaskins/swift,zisko/swift,shahmishal/swift,tjw/swift,hughbe/swift,austinzheng/swift,practicalswift/swift,huonw/swift,natecook1000/swift,alblue/swift,natecook1000/swift,JGiola/swift,hooman/swift,tkremenek/swift,apple/swift,lorentey/swift,sschiau/swift,danielmartin/swift,amraboelela/swift,glessard/swift,hooman/swift,CodaFi/swift,OscarSwanros/swift,deyton/swift,Jnosh/swift,felix91gr/swift,brentdax/swift,calebd/swift,jtbandes/swift,stephentyrone/swift,hughbe/swift,karwa/swift,gribozavr/swift,austinzheng/swift,swiftix/swift,brentdax/swift,parkera/swift,brentdax/swift,gregomni/swift,rudkx/swift,ahoppen/swift,amraboelela/swift,nathawes/swift,benlangmuir/swift,tkremenek/swift,rudkx/swift,shajrawi/swift,ahoppen/swift,allevato/swift,JGiola/swift,xwu/swift,apple/swift,brentdax/swift,jckarter/swift,felix91gr/swift,jmgc/swift,roambotics/swift,milseman/swift,gregomni/swift,gribozavr/swift,shahmishal/swift,natecook1000/swift,jopamer/swift,deyton/swift,apple/swift,frootloops/swift,huonw/swift,harlanhaskins/swift,frootloops/swift,benlangmuir/swift,uasys/swift,lorentey/swift,huonw/swift,sschiau/swift,natecook1000/swift,lorentey/swift,Jnosh/swift,return/swift,OscarSwanros/swift,amraboelela/swift,JGiola/swift,parkera/swift,nathawes/swift,milseman/swift,jmgc/swift,aschwaighofer/swift,calebd/swift,lorentey/swift,stephentyrone/swift,lorentey/swift,OscarSwanros/swift,devincoughlin/swift,gribozavr/swift,apple/swift,danielmartin/swift,parkera/swift,calebd/swift,stephentyrone/swift,jckarter/swift,devincoughlin/swift,deyton/swift,sschiau/swift,hughbe/swift,stephentyrone/swift,rudkx/swift,sschiau/swift,sschiau/swift,lorentey/swift,austinzheng/swift,OscarSwanros/swift