Correctly support -default-to-nil-allocator for all platforms

core/runtime/default_allocators_nil.odin

@@ -1,17 +1,38 @@
-//+build freestanding
 package runtime
 
-// mem.nil_allocator reimplementation
-
-default_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode,
+nil_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode,
                                size, alignment: int,
                                old_memory: rawptr, old_size: int, loc := #caller_location) -> ([]byte, Allocator_Error) {
+	switch mode {
+	case .Alloc:
+		return nil, .Out_Of_Memory
+	case .Free:
+		return nil, .None
+	case .Free_All:
+		return nil, .Mode_Not_Implemented
+	case .Resize:
+		if size == 0 {
+			return nil, .None
+		}
+		return nil, .Out_Of_Memory
+	case .Query_Features:
+		return nil, .Mode_Not_Implemented
+	case .Query_Info:
+		return nil, .Mode_Not_Implemented
+	}
 	return nil, .None
 }
 
-default_allocator :: proc() -> Allocator {
+nil_allocator :: proc() -> Allocator {
 	return Allocator{
-		procedure = default_allocator_proc,
+		procedure = nil_allocator_proc,
 		data = nil,
 	}
 }
+
+
+
+when ODIN_OS == "freestanding" {
+	default_allocator_proc :: nil_allocator_proc
+	default_allocator :: nil_allocator
+}