legacy junk compatibility grab-bag

- add the rest of the junk traditionally in sys/param.h
- add prototypes for some nonstandard functions
- add _GNU_SOURCE to their source files so the compiler can check proto

include/sys/param.h

@@ -1,20 +1,35 @@
-#undef MAXSYMLINKS
+#ifndef _SYS_PARAM_H
+#define _SYS_PARAM_H
+
 #define MAXSYMLINKS 20
-
-#undef MAXHOSTNAMELEN
 #define MAXHOSTNAMELEN 64
-
-#undef MAXNAMLEN
 #define MAXNAMLEN 255
-
-#undef MAXPATHLEN
 #define MAXPATHLEN 4096
+#define NBBY 8
+#define NGROUPS 32
+#define CANBSIZE 255
+#define NOFILE 256
+#define NCARGS 131072
+#define DEV_BSIZE 512
+#define NOGROUP (-1)
 
 #undef MIN
 #undef MAX
 #define MIN(a,b) (((a)<(b))?(a):(b))
 #define MAX(a,b) (((a)>(b))?(a):(b))
 
+#define ___bitop(x,i,o) ((a)[(i)/8] o 1<<(i)%8)
+#define setbit(x,i) __bitop(x,i,|=)
+#define clrbit(x,i) __bitop(x,i,&=~)
+#define isset(x,i) __bitop(x,i,&)
+#define isclr(x,i) !isset(x,i)
+
+#define howmany(n,d) (((n)+((d)-1))/(d))
+#define roundup(n,d) (howmany(n,d)*(d))
+#define powerof2(n) !(((n)-1) & (n))
+
 #include <sys/resource.h>
 #include <endian.h>
 #include <limits.h>
+
+#endif