Move os stuff to OS specific files

core/crypto/hash/hash_freestanding.odin

@@ -0,0 +1,10 @@
+//+build freestanding
+package crypto_hash
+
+hash :: proc {
+	hash_stream,
+	hash_bytes,
+	hash_string,
+	hash_bytes_to_buffer,
+	hash_string_to_buffer,
+}