error: this statement may fall through

[bboysteed]

when i run make,i get this error
coffgen.c:2103:8: error: this statement may fall through [-Werror=implicit-fallthrough=]
if (combined->u.syment.n_type == T_NULL)
^
coffgen.c:2120:3: note: here
case C_EXT:
^~~~
coffgen.c:2122:8: error: this statement may fall through [-Werror=implicit-fallthrough=]
if (ISFCN (combined->u.syment.n_type))
^
coffgen.c:2140:3: note: here
default:
^~~~~~~