Misc performance tweaks (#4509)

* use Array.Empty() where instead of allocating new zero-length arrays

* structure for loops in a way that the JIT will elide array/Span bounds checking

* avoiding function calls in for loop condition tests

* avoid LINQ in a hot path

* conform with code style

* fix mistake in GetNextWaitingObject()

* fix GetNextWaitingObject() possibility of returning null if all list items have TimePoint == long.MaxValue

* make GetNextWaitingObject() behave FIFO behavior for multiple items with the same TimePoint

Ryujinx.HLE/HOS/Services/Time/TimeZone/TimeZoneContentManager.cs

@@ -233,7 +233,7 @@ namespace Ryujinx.HLE.HOS.Services.Time.TimeZone
                 // If the location name is too long, error out.
                 if (locationName.Length > 0x24)
                 {
-                    outLocationNameArray = new string[0];
+                    outLocationNameArray = Array.Empty<string>();
 
                     return ResultCode.LocationNameTooLong;
                 }