Allow builds on platforms with unsigned chars by default
Allow builds on platforms with unsigned chars by default

Certain architectures, such as ARM, use unsigned chars by default
so require the `-fsigned-char` for certain value comparisons to
make sense and in order to compile.

MiCHiLU/flatbuffers,rw/flatbuffers,google/flatbuffers,rw/flatbuffers,hgl888/flatbuffers,vitalyisaev2/flatbuffers,alexames/flatbuffers,royalharsh/flatbuffers,jbrads/flatbuffers,jasonstubbs/flatbuffers,jekinchen/flatjni,bog-dan-ro/flatbuffers,chenkai036/flatbuffers,endorph-soft/flatbuffers,rw/flatbuffers,kiyoto-suzuki/flatbuffers,chenkai036/flatbuffers,benssson/flatbuffers,alexames/flatbuffers,stewartmiles/flatbuffers,chenkai036/flatbuffers,splhack/flatbuffers,rw/flatbuffers,SinbadFreedom/FlatBuffer,kadirahq/flatbuffers,zarianw/flatbuffers,alexames/flatbuffers,eburkitt/flatbuffers,eburkitt/flatbuffers,evolutional/flatbuffers,benssson/flatbuffers,FrankStain/flatbuffers,rw/flatbuffers,alexames/flatbuffers,pjulien/flatbuffers,google/flatbuffers,vitalyisaev2/flatbuffers,google/flatbuffers,bog-dan-ro/flatbuffers,alexames/flatbuffers,pjulien/flatbuffers,fuchsia-mirror/third_party-flatbuffers,pjulien/flatbuffers,zarianw/flatbuffers,royalharsh/flatbuffers,DavadDi/flatbuffers,bog-dan-ro/flatbuffers,royalharsh/flatbuffers,kadirahq/flatbuffers,google/flatbuffers,google/flatbuffers,stewartmiles/flatbuffers,jekinchen/flatjni,stewartmiles/flatbuffers,zarianw/flatbuffers,stewartmiles/flatbuffers,DavadDi/flatbuffers,chenkai036/flatbuffers,pjulien/flatbuffers,endorph-soft/flatbuffers,eburkitt/flatbuffers,vitalyisaev2/flatbuffers,chenkai036/flatbuffers,splhack/flatbuffers,fuchsia-mirror/third_party-flatbuffers,SinbadFreedom/FlatBuffer,endorph-soft/flatbuffers,kiyoto-suzuki/flatbuffers,chenkai036/flatbuffers,SinbadFreedom/FlatBuffer,zarianw/flatbuffers,DavadDi/flatbuffers,google/flatbuffers,benssson/flatbuffers,royalharsh/flatbuffers,evolutional/flatbuffers,vitalyisaev2/flatbuffers,SinbadFreedom/FlatBuffer,pjulien/flatbuffers,FrankStain/flatbuffers,kiyoto-suzuki/flatbuffers,hgl888/flatbuffers,google/flatbuffers,rw/flatbuffers,evolutional/flatbuffers,zarianw/flatbuffers,kadirahq/flatbuffers,DavadDi/flatbuffers,stewartmiles/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,rw/flatbuffers,hgl888/flatbuffers,endorph-soft/flatbuffers,jasonstubbs/flatbuffers,splhack/flatbuffers,google/flatbuffers,splhack/flatbuffers,kadirahq/flatbuffers,FrankStain/flatbuffers,alexames/flatbuffers,MiCHiLU/flatbuffers,vitalyisaev2/flatbuffers,google/flatbuffers,royalharsh/flatbuffers,zarianw/flatbuffers,stewartmiles/flatbuffers,jbrads/flatbuffers,jbrads/flatbuffers,alexames/flatbuffers,google/flatbuffers,hgl888/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,DavadDi/flatbuffers,eburkitt/flatbuffers,hgl888/flatbuffers,google/flatbuffers,jekinchen/flatjni,jasonstubbs/flatbuffers,kiyoto-suzuki/flatbuffers,MiCHiLU/flatbuffers,benssson/flatbuffers,jasonstubbs/flatbuffers,alexames/flatbuffers,rw/flatbuffers,SinbadFreedom/FlatBuffer,kiyoto-suzuki/flatbuffers,pjulien/flatbuffers,alexames/flatbuffers,jekinchen/flatjni,jbrads/flatbuffers,rw/flatbuffers,fuchsia-mirror/third_party-flatbuffers,MiCHiLU/flatbuffers,bog-dan-ro/flatbuffers,MiCHiLU/flatbuffers,kadirahq/flatbuffers,jbrads/flatbuffers,royalharsh/flatbuffers,kadirahq/flatbuffers,stewartmiles/flatbuffers,evolutional/flatbuffers,google/flatbuffers,evolutional/flatbuffers,SinbadFreedom/FlatBuffer,bog-dan-ro/flatbuffers,evolutional/flatbuffers,jbrads/flatbuffers,pjulien/flatbuffers,FrankStain/flatbuffers,alexames/flatbuffers,rw/flatbuffers,MiCHiLU/flatbuffers,jbrads/flatbuffers,jekinchen/flatjni,FrankStain/flatbuffers,fuchsia-mirror/third_party-flatbuffers,evolutional/flatbuffers,eburkitt/flatbuffers,alexames/flatbuffers,bog-dan-ro/flatbuffers,jekinchen/flatjni,rw/flatbuffers,stewartmiles/flatbuffers,benssson/flatbuffers,fuchsia-mirror/third_party-flatbuffers,endorph-soft/flatbuffers,fuchsia-mirror/third_party-flatbuffers,vitalyisaev2/flatbuffers,kadirahq/flatbuffers,alexames/flatbuffers,jasonstubbs/flatbuffers,zarianw/flatbuffers,endorph-soft/flatbuffers,jekinchen/flatjni,kiyoto-suzuki/flatbuffers,MiCHiLU/flatbuffers,FrankStain/flatbuffers,benssson/flatbuffers,rw/flatbuffers,stewartmiles/flatbuffers,DavadDi/flatbuffers,pjulien/flatbuffers,jekinchen/flatjni,eburkitt/flatbuffers,jekinchen/flatjni,chenkai036/flatbuffers,hgl888/flatbuffers,MiCHiLU/flatbuffers,splhack/flatbuffers,eburkitt/flatbuffers,endorph-soft/flatbuffers,kiyoto-suzuki/flatbuffers,royalharsh/flatbuffers,chenkai036/flatbuffers,pjulien/flatbuffers,FrankStain/flatbuffers,royalharsh/flatbuffers,evolutional/flatbuffers,jbrads/flatbuffers,pjulien/flatbuffers,evolutional/flatbuffers,SinbadFreedom/FlatBuffer,google/flatbuffers,splhack/flatbuffers,royalharsh/flatbuffers,benssson/flatbuffers,pjulien/flatbuffers,fuchsia-mirror/third_party-flatbuffers,chenkai036/flatbuffers,endorph-soft/flatbuffers,fuchsia-mirror/third_party-flatbuffers,evolutional/flatbuffers,kiyoto-suzuki/flatbuffers,kadirahq/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,bog-dan-ro/flatbuffers,vitalyisaev2/flatbuffers,benssson/flatbuffers,jekinchen/flatjni,alexames/flatbuffers,stewartmiles/flatbuffers,alexames/flatbuffers,jasonstubbs/flatbuffers,eburkitt/flatbuffers,vitalyisaev2/flatbuffers,SinbadFreedom/FlatBuffer,FrankStain/flatbuffers,zarianw/flatbuffers,alexames/flatbuffers,splhack/flatbuffers,pjulien/flatbuffers,evolutional/flatbuffers,chenkai036/flatbuffers,splhack/flatbuffers,royalharsh/flatbuffers,kiyoto-suzuki/flatbuffers,stewartmiles/flatbuffers,bog-dan-ro/flatbuffers,jasonstubbs/flatbuffers,endorph-soft/flatbuffers,endorph-soft/flatbuffers,jasonstubbs/flatbuffers