Fix more clangd errors

This also seems to fix the problem where clangd failed to index most header files, which was due to the typo in JGeometry.h.

include/JSystem/JGeometry.h

@@ -320,7 +320,7 @@ struct TVec2 {
 template <class T>
 struct TBox {
     TBox() : i(), f() {}
-    TBox(const TBox& other) : i(other.f), f(other.y) {}
+    TBox(const TBox& other) : i(other.i), f(other.f) {}
 
     T i, f;
 };

include/dolphin/os/OSTime.h

@@ -30,7 +30,7 @@ OSTime OSGetTime(void);
 OSTick OSGetTick(void);
 OSTime __OSGetSystemTime(void);
 OSTime __OSTimeToSystemTime(OSTime time);
-void GetDates(s32 days, OSCalendarTime* ct);
+static void GetDates(s32 days, OSCalendarTime* ct);
 void OSTicksToCalendarTime(OSTime ticks, OSCalendarTime* ct);
 
 extern u32 __OSBusClock AT_ADDRESS(0x800000F8);