allow pointers as keys in maps, treating them the same as ints - ptr eq not value equality

R=ken,gri
OCL=13879
CL=13879

src/runtime/map.c

@@ -40,7 +40,7 @@ sys·newmap(uint32 keysize, uint32 valsize,
 {
 	Hmap *m;
 
-	if(keyalg >= 2 ||
+	if(keyalg >= 3 ||
 	   valalg >= 3) {
 		prints("0<=");
 		sys·printint(keyalg);

src/runtime/runtime.c

@@ -777,7 +777,8 @@ pointercopy(uint32 s, void **a, void **b)
 Alg
 algarray[3] =
 {
-	{	&memhash,	&memequal,	&memprint,	&memcopy	},
-	{	&stringhash,	&stringequal,	&stringprint,	&stringcopy	},
-	{	&pointerhash,	&pointerequal,	&pointerprint,	&pointercopy	},
+	{	&memhash,	&memequal,	&memprint,	&memcopy	},  // 0
+	{	&stringhash,	&stringequal,	&stringprint,	&stringcopy	},  // 1
+//	{	&pointerhash,	&pointerequal,	&pointerprint,	&pointercopy	},  // 2
+	{	&memhash,	&memequal,	&memprint,	&memcopy	},  // 2 - treat pointers as ints
 };