[ClangImporter] Remove option implied by -fmodules. (#6452)
[ClangImporter] Remove option implied by -fmodules. (#6452)

No functionality change. This goes all the way back to when we used to
set up the importer using clang -cc1 arguments instead of driver
(GCC-like) arguments.
stephentyrone/swift,parkera/swift,codestergit/swift,harlanhaskins/swift,huonw/swift,calebd/swift,gribozavr/swift,roambotics/swift,benlangmuir/swift,shahmishal/swift,aschwaighofer/swift,practicalswift/swift,gribozavr/swift,codestergit/swift,felix91gr/swift,tardieu/swift,tjw/swift,shajrawi/swift,xwu/swift,gmilos/swift,xwu/swift,rudkx/swift,felix91gr/swift,gregomni/swift,arvedviehweger/swift,jmgc/swift,gribozavr/swift,jmgc/swift,austinzheng/swift,roambotics/swift,lorentey/swift,shajrawi/swift,aschwaighofer/swift,harlanhaskins/swift,airspeedswift/swift,felix91gr/swift,djwbrown/swift,tinysun212/swift-windows,Jnosh/swift,nathawes/swift,therealbnut/swift,tkremenek/swift,parkera/swift,huonw/swift,devincoughlin/swift,natecook1000/swift,allevato/swift,codestergit/swift,OscarSwanros/swift,deyton/swift,milseman/swift,gottesmm/swift,Jnosh/swift,jtbandes/swift,airspeedswift/swift,karwa/swift,natecook1000/swift,tkremenek/swift,jmgc/swift,Jnosh/swift,xwu/swift,manavgabhawala/swift,natecook1000/swift,nathawes/swift,deyton/swift,karwa/swift,uasys/swift,manavgabhawala/swift,jtbandes/swift,arvedviehweger/swift,glessard/swift,milseman/swift,allevato/swift,airspeedswift/swift,therealbnut/swift,Jnosh/swift,harlanhaskins/swift,danielmartin/swift,CodaFi/swift,tjw/swift,lorentey/swift,return/swift,arvedviehweger/swift,glessard/swift,bitjammer/swift,zisko/swift,djwbrown/swift,aschwaighofer/swift,tinysun212/swift-windows,tkremenek/swift,tinysun212/swift-windows,rudkx/swift,brentdax/swift,hooman/swift,zisko/swift,hughbe/swift,swiftix/swift,austinzheng/swift,apple/swift,therealbnut/swift,tardieu/swift,parkera/swift,austinzheng/swift,amraboelela/swift,CodaFi/swift,gribozavr/swift,jtbandes/swift,alblue/swift,huonw/swift,devincoughlin/swift,atrick/swift,brentdax/swift,amraboelela/swift,xedin/swift,karwa/swift,OscarSwanros/swift,austinzheng/swift,uasys/swift,karwa/swift,calebd/swift,rudkx/swift,aschwaighofer/swift,uasys/swift,arvedviehweger/swift,gottesmm/swift,swiftix/swift,sschiau/swift,tkremenek/swift,hughbe/swift,shahmishal/swift,zisko/swift,karwa/swift,ahoppen/swift,arvedviehweger/swift,hughbe/swift,practicalswift/swift,rudkx/swift,gribozavr/swift,therealbnut/swift,tardieu/swift,calebd/swift,sschiau/swift,ahoppen/swift,deyton/swift,deyton/swift,harlanhaskins/swift,practicalswift/swift,hooman/swift,devincoughlin/swift,jopamer/swift,sschiau/swift,djwbrown/swift,tardieu/swift,lorentey/swift,deyton/swift,xedin/swift,felix91gr/swift,therealbnut/swift,stephentyrone/swift,stephentyrone/swift,gottesmm/swift,shahmishal/swift,uasys/swift,jckarter/swift,danielmartin/swift,milseman/swift,atrick/swift,atrick/swift,hooman/swift,alblue/swift,amraboelela/swift,apple/swift,Jnosh/swift,huonw/swift,apple/swift,shajrawi/swift,tkremenek/swift,roambotics/swift,JGiola/swift,tjw/swift,bitjammer/swift,jmgc/swift,djwbrown/swift,lorentey/swift,OscarSwanros/swift,airspeedswift/swift,tjw/swift,felix91gr/swift,benlangmuir/swift,tinysun212/swift-windows,therealbnut/swift,practicalswift/swift,airspeedswift/swift,uasys/swift,gmilos/swift,CodaFi/swift,aschwaighofer/swift,tardieu/swift,stephentyrone/swift,danielmartin/swift,gottesmm/swift,jmgc/swift,bitjammer/swift,danielmartin/swift,glessard/swift,roambotics/swift,gmilos/swift,nathawes/swift,frootloops/swift,gribozavr/swift,milseman/swift,glessard/swift,gribozavr/swift,airspeedswift/swift,jtbandes/swift,jtbandes/swift,return/swift,zisko/swift,manavgabhawala/swift,xedin/swift,austinzheng/swift,djwbrown/swift,JGiola/swift,apple/swift,frootloops/swift,bitjammer/swift,benlangmuir/swift,shajrawi/swift,allevato/swift,ahoppen/swift,rudkx/swift,aschwaighofer/swift,arvedviehweger/swift,hooman/swift,gregomni/swift,JaSpa/swift,gmilos/swift,codestergit/swift,ahoppen/swift,djwbrown/swift,return/swift,danielmartin/swift,huonw/swift,gmilos/swift,amraboelela/swift,tinysun212/swift-windows,therealbnut/swift,swiftix/swift,swiftix/swift,JaSpa/swift,jckarter/swift,atrick/swift,parkera/swift,practicalswift/swift,return/swift,danielmartin/swift,devincoughlin/swift,codestergit/swift,ahoppen/swift,lorentey/swift,natecook1000/swift,xwu/swift,return/swift,djwbrown/swift,roambotics/swift,uasys/swift,benlangmuir/swift,JaSpa/swift,deyton/swift,gmilos/swift,sschiau/swift,amraboelela/swift,JaSpa/swift,swiftix/swift,manavgabhawala/swift,brentdax/swift,deyton/swift,practicalswift/swift,stephentyrone/swift,alblue/swift,return/swift,jopamer/swift,hughbe/swift,devincoughlin/swift,gmilos/swift,brentdax/swift,codestergit/swift,lorentey/swift,tinysun212/swift-windows,alblue/swift,jckarter/swift,calebd/swift,danielmartin/swift,zisko/swift,milseman/swift,tkremenek/swift,ahoppen/swift,jmgc/swift,jopamer/swift,karwa/swift,amraboelela/swift,allevato/swift,karwa/swift,practicalswift/swift,natecook1000/swift,devincoughlin/swift,milseman/swift,gregomni/swift,glessard/swift,bitjammer/swift,JGiola/swift,brentdax/swift,tjw/swift,gottesmm/swift,nathawes/swift,brentdax/swift,Jnosh/swift,CodaFi/swift,codestergit/swift,jopamer/swift,jopamer/swift,frootloops/swift,jopamer/swift,parkera/swift,gregomni/swift,CodaFi/swift,xwu/swift,felix91gr/swift,shahmishal/swift,Jnosh/swift,airspeedswift/swift,practicalswift/swift,bitjammer/swift,shajrawi/swift,allevato/swift,huonw/swift,allevato/swift,manavgabhawala/swift,tinysun212/swift-windows,xedin/swift,harlanhaskins/swift,manavgabhawala/swift,CodaFi/swift,return/swift,calebd/swift,shahmishal/swift,lorentey/swift,JaSpa/swift,arvedviehweger/swift,tardieu/swift,gregomni/swift,xedin/swift,frootloops/swift,sschiau/swift,tjw/swift,frootloops/swift,amraboelela/swift,shahmishal/swift,parkera/swift,xwu/swift,alblue/swift,parkera/swift,shajrawi/swift,natecook1000/swift,jmgc/swift,swiftix/swift,zisko/swift,aschwaighofer/swift,JGiola/swift,JaSpa/swift,JGiola/swift,JGiola/swift,harlanhaskins/swift,stephentyrone/swift,parkera/swift,karwa/swift,nathawes/swift,huonw/swift,jckarter/swift,OscarSwanros/swift,nathawes/swift,roambotics/swift,OscarSwanros/swift,alblue/swift,shahmishal/swift,tkremenek/swift,sschiau/swift,jckarter/swift,harlanhaskins/swift,nathawes/swift,glessard/swift,hughbe/swift,atrick/swift,shajrawi/swift,austinzheng/swift,hooman/swift,jckarter/swift,xedin/swift,stephentyrone/swift,sschiau/swift,devincoughlin/swift,hughbe/swift,gribozavr/swift,apple/swift,gottesmm/swift,devincoughlin/swift,tardieu/swift,OscarSwanros/swift,allevato/swift,xwu/swift,frootloops/swift,jtbandes/swift,hooman/swift,austinzheng/swift,atrick/swift,xedin/swift,OscarSwanros/swift,shahmishal/swift,jopamer/swift,natecook1000/swift,manavgabhawala/swift,hooman/swift,uasys/swift,benlangmuir/swift,jtbandes/swift,JaSpa/swift,brentdax/swift,gregomni/swift,apple/swift,swiftix/swift,calebd/swift,milseman/swift,shajrawi/swift,rudkx/swift,hughbe/swift,gottesmm/swift,calebd/swift,sschiau/swift,tjw/swift,alblue/swift,frootloops/swift,lorentey/swift,jckarter/swift,CodaFi/swift,xedin/swift,benlangmuir/swift,bitjammer/swift,felix91gr/swift,zisko/swift