Use Common::ToLower and Common::ToUpper

Source/Core/Common/IniFile.h

@@ -4,7 +4,6 @@
 #pragma once
 
 #include <algorithm>
-#include <cctype>
 #include <list>
 #include <map>
 #include <string>
@@ -22,9 +21,8 @@ struct CaseInsensitiveStringCompare
   bool operator()(std::string_view a, std::string_view b) const
   {
     return std::lexicographical_compare(
-        a.begin(), a.end(), b.begin(), b.end(), [](char lhs, char rhs) {
-          return std::tolower(static_cast<u8>(lhs)) < std::tolower(static_cast<u8>(rhs));
-        });
+        a.begin(), a.end(), b.begin(), b.end(),
+        [](char lhs, char rhs) { return Common::ToLower(lhs) < Common::ToLower(rhs); });
   }
 
   static bool IsEqual(std::string_view a, std::string_view b)
@@ -33,7 +31,7 @@ struct CaseInsensitiveStringCompare
       return false;
 
     return std::equal(a.begin(), a.end(), b.begin(), b.end(), [](char lhs, char rhs) {
-      return std::tolower(static_cast<u8>(lhs)) == std::tolower(static_cast<u8>(rhs));
+      return Common::ToLower(lhs) == Common::ToLower(rhs);
     });
   }
 };

Source/Core/Common/Logging/LogManager.cpp

@@ -101,8 +101,7 @@ static size_t DeterminePathCutOffPoint()
   constexpr const char* pattern2 = "\\source\\core\\";
 #endif
   std::string path = __FILE__;
-  std::transform(path.begin(), path.end(), path.begin(),
-                 [](char c) { return std::tolower(c, std::locale::classic()); });
+  Common::ToLower(&path);
   size_t pos = path.find(pattern);
 #ifdef _WIN32
   if (pos == std::string::npos)

Source/Core/Common/Network.cpp

@@ -4,7 +4,6 @@
 #include "Common/Network.h"
 
 #include <algorithm>
-#include <cctype>
 #include <string_view>
 
 #ifndef _WIN32
@@ -18,6 +17,7 @@
 #include <fmt/format.h>
 
 #include "Common/Random.h"
+#include "Common/StringUtil.h"
 
 namespace Common
 {
@@ -59,7 +59,7 @@ std::optional<MACAddress> StringToMacAddress(std::string_view mac_string)
 
   for (size_t i = 0; i < mac_string.size() && x < (MAC_ADDRESS_SIZE * 2); ++i)
   {
-    char c = tolower(mac_string.at(i));
+    char c = Common::ToLower(mac_string.at(i));
     if (c >= '0' && c <= '9')
     {
       mac[x / 2] |= (c - '0') << ((x & 1) ? 0 : 4);