Remove the -Wno-unused-function hider. Should be able to fix these with this method if any more crop up on Linux.

Author: chief1983

configure.ac

@@ -251,7 +251,7 @@ fi
 
 if test "$fs2_debug" = "yes" ; then
 	AC_DEFINE([_DEBUG])
-	D_CFLAGS="$D_CFLAGS -O0 -g -Wall -Wextra -Wno-unused-parameter -Wno-unused-function -Wno-write-strings -Wshadow -funroll-loops"
+	D_CFLAGS="$D_CFLAGS -O0 -g -Wall -Wextra -Wno-unused-parameter -Wno-write-strings -Wshadow -funroll-loops"
 	D_LDFLAGS="$D_LDFLAGS -g"
 
 	if test "$fs2_fred" = "yes" ; then
@@ -262,7 +262,7 @@ if test "$fs2_debug" = "yes" ; then
 else
 	AC_DEFINE([NDEBUG])
 	D_CFLAGS="$D_CFLAGS -O2 -Wall -funroll-loops"
-	D_CFLAGS="$D_CFLAGS -Wno-unused-function -Wno-write-strings -Wno-unused-variable"
+	D_CFLAGS="$D_CFLAGS -Wno-write-strings -Wno-unused-variable"
 
 	AC_C_COMPILE_FLAGS([-Wno-unused-but-set-variable])