CPP:Improve CMakeLists to not build a shared library when RE2 is used and not available as a shared library.
CPP:Improve CMakeLists to not build a shared library when RE2 is used and not available as a shared library.

hejunbinlan/libphonenumber,shelsonjava/libphonenumber,google/libphonenumber,keghani/libphonenumber,mtownsen/libphonenumber,JasOXIII/libphonenumber,lcorbasson/libphonenumber,shelsonjava/libphonenumber,weitzhandler/libphonenumber,pplatek/libphonenumber,keghani/libphonenumber,mlevytskiy/libphonenumber,seegno-forks/libphonenumber,mistrydarshan99/libphonenumber,gautier-gdx/libphonenumber,seegno-forks/libphonenumber,mistrydarshan99/libphonenumber,keghani/libphonenumber,lcorbasson/libphonenumber,waveremit/libphonenumber,fishman1986/libphonenumber,mcanthony/libphonenumber,joharmandav/libphonenumber,pchero/libphonenumber,mlevytskiy/libphonenumber,gautier-gdx/libphonenumber,mcanthony/libphonenumber,javimey/libphonenumber,johnnyshields/libphonenumber,karimhb/libphonenumber,mtownsen/libphonenumber,mlevytskiy/libphonenumber,dpocock/libphonenumber,roes/libphonenumber,gautier-gdx/libphonenumber,shelsonjava/libphonenumber,alecx/libphonenumber,weitzhandler/libphonenumber,javimey/libphonenumber,ceosilvajr/libphonenumber,johnnyshields/libphonenumber,karimhb/libphonenumber,google/libphonenumber,pplatek/libphonenumber,alecx/libphonenumber,roes/libphonenumber,hejunbinlan/libphonenumber,fishman1986/libphonenumber,waveremit/libphonenumber,gautier-gdx/libphonenumber,mihaelacr-google/libphonenumber,joharmandav/libphonenumber,google/libphonenumber,seegno-forks/libphonenumber,roes/libphonenumber,digideskio/libphonenumber,alucic/libphonenumber,mujiansu/libphonenumber,ceosilvajr/libphonenumber,google/libphonenumber,roes/libphonenumber,mihaelacr-google/libphonenumber,keghani/libphonenumber,alecx/libphonenumber,johnnyshields/libphonenumber,mcanthony/libphonenumber,digideskio/libphonenumber,alucic/libphonenumber,ceosilvajr/libphonenumber,pchero/libphonenumber,stevenliuit/libphonenumber,johnnyshields/libphonenumber,Corei13/libphonenumber,Corei13/libphonenumber,lcorbasson/libphonenumber,JasOXIII/libphonenumber,tg123/libphonenumber,lcorbasson/libphonenumber,gautier-gdx/libphonenumber,mihaelacr-google/libphonenumber,digideskio/libphonenumber,mtownsen/libphonenumber,Corei13/libphonenumber,mtownsen/libphonenumber,stevenliuit/libphonenumber,joharmandav/libphonenumber,dpocock/libphonenumber,tg123/libphonenumber,shelsonjava/libphonenumber,pplatek/libphonenumber,stevenliuit/libphonenumber,mistrydarshan99/libphonenumber,lcorbasson/libphonenumber,alecx/libphonenumber,waveremit/libphonenumber,alucic/libphonenumber,mihaelacr-google/libphonenumber,JasOXIII/libphonenumber,roes/libphonenumber,waveremit/libphonenumber,ceosilvajr/libphonenumber,javimey/libphonenumber,alucic/libphonenumber,mihaelacr-google/libphonenumber,digideskio/libphonenumber,dpocock/libphonenumber,joharmandav/libphonenumber,tg123/libphonenumber,mlevytskiy/libphonenumber,google/libphonenumber,fishman1986/libphonenumber,alucic/libphonenumber,google/libphonenumber,stevenliuit/libphonenumber,weitzhandler/libphonenumber,JasOXIII/libphonenumber,mujiansu/libphonenumber,mcanthony/libphonenumber,tg123/libphonenumber,karimhb/libphonenumber,mlevytskiy/libphonenumber,seegno-forks/libphonenumber,tg123/libphonenumber,joharmandav/libphonenumber,karimhb/libphonenumber,pplatek/libphonenumber,mcanthony/libphonenumber,JasOXIII/libphonenumber,mujiansu/libphonenumber,mujiansu/libphonenumber,weitzhandler/libphonenumber,pchero/libphonenumber,weitzhandler/libphonenumber,pchero/libphonenumber,javimey/libphonenumber,mistrydarshan99/libphonenumber,alecx/libphonenumber,fishman1986/libphonenumber,dpocock/libphonenumber,javimey/libphonenumber,mistrydarshan99/libphonenumber,Corei13/libphonenumber,mtownsen/libphonenumber,digideskio/libphonenumber,ceosilvajr/libphonenumber,karimhb/libphonenumber,hejunbinlan/libphonenumber,shelsonjava/libphonenumber,keghani/libphonenumber,johnnyshields/libphonenumber,stevenliuit/libphonenumber,hejunbinlan/libphonenumber,pplatek/libphonenumber,fishman1986/libphonenumber,pchero/libphonenumber,waveremit/libphonenumber,mujiansu/libphonenumber,dpocock/libphonenumber,Corei13/libphonenumber,hejunbinlan/libphonenumber