[AST] Disable comment printing while emitting diagnostics
[AST] Disable comment printing while emitting diagnostics

There is a problem in PCH builds where source manager might
end up having unorderable source locations for comments, to work
around this (which is going to be fixed separately) let's
disable comment printing while emitting diagnostics since
such comments are not required.

Resolves: rdar://problem/38203776

karwa/swift,tjw/swift,apple/swift,sschiau/swift,nathawes/swift,shahmishal/swift,roambotics/swift,huonw/swift,alblue/swift,lorentey/swift,gribozavr/swift,practicalswift/swift,ahoppen/swift,hooman/swift,stephentyrone/swift,parkera/swift,aschwaighofer/swift,karwa/swift,parkera/swift,danielmartin/swift,roambotics/swift,tkremenek/swift,gregomni/swift,shahmishal/swift,stephentyrone/swift,rudkx/swift,devincoughlin/swift,glessard/swift,jckarter/swift,brentdax/swift,natecook1000/swift,huonw/swift,shajrawi/swift,gribozavr/swift,jopamer/swift,amraboelela/swift,jckarter/swift,harlanhaskins/swift,ahoppen/swift,gribozavr/swift,gribozavr/swift,jopamer/swift,harlanhaskins/swift,lorentey/swift,apple/swift,jopamer/swift,amraboelela/swift,alblue/swift,nathawes/swift,roambotics/swift,huonw/swift,natecook1000/swift,gregomni/swift,CodaFi/swift,allevato/swift,xwu/swift,nathawes/swift,benlangmuir/swift,atrick/swift,atrick/swift,sschiau/swift,ahoppen/swift,allevato/swift,karwa/swift,amraboelela/swift,apple/swift,glessard/swift,aschwaighofer/swift,devincoughlin/swift,tkremenek/swift,huonw/swift,xwu/swift,allevato/swift,allevato/swift,austinzheng/swift,allevato/swift,danielmartin/swift,amraboelela/swift,jmgc/swift,brentdax/swift,brentdax/swift,benlangmuir/swift,practicalswift/swift,alblue/swift,jckarter/swift,alblue/swift,atrick/swift,practicalswift/swift,tjw/swift,practicalswift/swift,airspeedswift/swift,xedin/swift,gregomni/swift,shajrawi/swift,stephentyrone/swift,austinzheng/swift,sschiau/swift,lorentey/swift,parkera/swift,harlanhaskins/swift,tkremenek/swift,practicalswift/swift,xedin/swift,lorentey/swift,jmgc/swift,gribozavr/swift,atrick/swift,nathawes/swift,tjw/swift,airspeedswift/swift,apple/swift,ahoppen/swift,roambotics/swift,hooman/swift,roambotics/swift,aschwaighofer/swift,rudkx/swift,shajrawi/swift,stephentyrone/swift,JGiola/swift,hooman/swift,benlangmuir/swift,nathawes/swift,karwa/swift,xedin/swift,jmgc/swift,tkremenek/swift,aschwaighofer/swift,tjw/swift,jckarter/swift,glessard/swift,tkremenek/swift,benlangmuir/swift,practicalswift/swift,parkera/swift,tjw/swift,apple/swift,CodaFi/swift,jmgc/swift,natecook1000/swift,brentdax/swift,glessard/swift,austinzheng/swift,glessard/swift,shajrawi/swift,JGiola/swift,lorentey/swift,shahmishal/swift,jckarter/swift,hooman/swift,huonw/swift,jmgc/swift,jckarter/swift,glessard/swift,danielmartin/swift,xedin/swift,airspeedswift/swift,JGiola/swift,sschiau/swift,xedin/swift,sschiau/swift,gregomni/swift,natecook1000/swift,jopamer/swift,hooman/swift,karwa/swift,harlanhaskins/swift,danielmartin/swift,airspeedswift/swift,xedin/swift,danielmartin/swift,airspeedswift/swift,jmgc/swift,alblue/swift,CodaFi/swift,harlanhaskins/swift,practicalswift/swift,devincoughlin/swift,parkera/swift,brentdax/swift,natecook1000/swift,sschiau/swift,austinzheng/swift,xwu/swift,shahmishal/swift,parkera/swift,sschiau/swift,shajrawi/swift,xwu/swift,shajrawi/swift,apple/swift,gregomni/swift,xedin/swift,alblue/swift,xwu/swift,benlangmuir/swift,rudkx/swift,harlanhaskins/swift,aschwaighofer/swift,karwa/swift,rudkx/swift,rudkx/swift,devincoughlin/swift,gribozavr/swift,nathawes/swift,CodaFi/swift,JGiola/swift,aschwaighofer/swift,hooman/swift,gribozavr/swift,jopamer/swift,atrick/swift,lorentey/swift,shajrawi/swift,danielmartin/swift,jmgc/swift,tjw/swift,airspeedswift/swift,devincoughlin/swift,tjw/swift,amraboelela/swift,atrick/swift,danielmartin/swift,shahmishal/swift,austinzheng/swift,austinzheng/swift,tkremenek/swift,amraboelela/swift,shahmishal/swift,amraboelela/swift,allevato/swift,practicalswift/swift,ahoppen/swift,devincoughlin/swift,shahmishal/swift,parkera/swift,rudkx/swift,aschwaighofer/swift,xwu/swift,huonw/swift,shahmishal/swift,gregomni/swift,lorentey/swift,stephentyrone/swift,lorentey/swift,brentdax/swift,jopamer/swift,natecook1000/swift,devincoughlin/swift,CodaFi/swift,alblue/swift,tkremenek/swift,karwa/swift,hooman/swift,gribozavr/swift,sschiau/swift,devincoughlin/swift,allevato/swift,roambotics/swift,harlanhaskins/swift,JGiola/swift,austinzheng/swift,CodaFi/swift,stephentyrone/swift,shajrawi/swift,jopamer/swift,xwu/swift,stephentyrone/swift,parkera/swift,ahoppen/swift,JGiola/swift,natecook1000/swift,xedin/swift,benlangmuir/swift,CodaFi/swift,jckarter/swift,brentdax/swift,nathawes/swift,huonw/swift,karwa/swift,airspeedswift/swift