includes/std: Added more #pragma once to all stdlib files

includes/std/hash.pat

@@ -1,3 +1,5 @@
+#pragma once
+
 namespace std::hash {
 
     fn crc32(u128 address, u64 size, u32 init, u32 poly) {

includes/std/http.pat

@@ -1,3 +1,5 @@
+#pragma once
+
 namespace std::http {
 
     fn get(str url) {