Enforce core:builtin and core:intrinsics for imports

core/slice/map.odin

@@ -1,6 +1,6 @@
 package slice
 
-import "intrinsics"
+import "core:intrinsics"
 import "core:runtime"
 import "core:mem"
 

core/slice/slice.odin

@@ -1,7 +1,7 @@
 package slice
 
-import "intrinsics"
-import "builtin"
+import "core:intrinsics"
+import "core:builtin"
 import "core:math/bits"
 import "core:mem"
 

core/slice/sort.odin

@@ -1,6 +1,6 @@
 package slice
 
-import "intrinsics"
+import "core:intrinsics"
 _ :: intrinsics;
 
 ORD :: intrinsics.type_is_ordered;