Add default_allocators_wasi.odin

core/runtime/default_allocators_wasi.odin

@@ -0,0 +1,32 @@
+//+build wasi
+package runtime
+
+default_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 {
+	return Allocator{
+		procedure = default_allocator_proc,
+		data = nil,
+	}
+}