LibCrypto+LibTLS: Avoid unaligned reads and writes

This adds an `AK::ByteReader` to help with that so we don't duplicate
the logic all over the place.
No more `*(const u16*)` and `*(const u32*)` for anyone.
This should help a little with #7060.

AK/ByteReader.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+namespace AK {
+
+struct ByteReader {
+    static void store(u8* address, u16 value)
+    {
+        union {
+            u16 _16;
+            u8 _8[2];
+        } const v { ._16 = value };
+        __builtin_memcpy(address, v._8, 2);
+    }
+
+    static void store(u8* address, u32 value)
+    {
+        union {
+            u32 _32;
+            u8 _8[4];
+        } const v { ._32 = value };
+        __builtin_memcpy(address, v._8, 4);
+    }
+
+    static void load(const u8* address, u16& value)
+    {
+        union {
+            u16 _16;
+            u8 _8[2];
+        } v { ._16 = 0 };
+        __builtin_memcpy(&v._8, address, 2);
+        value = v._16;
+    }
+
+    static void load(const u8* address, u32& value)
+    {
+        union {
+            u32 _32;
+            u8 _8[4];
+        } v { ._32 = 0 };
+        __builtin_memcpy(&v._8, address, 4);
+        value = v._32;
+    }
+
+    static u16 load16(const u8* address)
+    {
+        u16 value;
+        load(address, value);
+        return value;
+    }
+
+    static u32 load32(const u8* address)
+    {
+        u32 value;
+        load(address, value);
+        return value;
+    }
+};
+
+}
+
+using AK::ByteReader;