Fix printf format warnings on mingw clang (#4626, #4183, #3592)

docs/CHANGELOG.txt

@@ -80,6 +80,7 @@ Other Changes:
 - Drag and Drop: Fixed using BeginDragDropSource() inside a BeginChild() that returned false. (#4515)
 - PlotHistogram: Fixed zero-line position when manually specifying min<0 and max>0. (#4349) [@filippocrocchini]
 - Misc: Added asserts for missing PopItemFlag() calls.
+- Misc: Fixed printf-style format checks on Clang+MinGW. (#4626, #4183, #3592) [@guusw]
 - IO: Added 'io.WantCaptureMouseUnlessPopupClose' alternative to `io.WantCaptureMouse'. (#4480)
   This allows apps to receive the click on void when that click is used to close popup (by default,
   clicking on a void when a popup is open will close the popup but not release io.WantCaptureMouse).

imgui.h

@@ -92,7 +92,7 @@ Index of this file:
 #endif
 
 // Helper Macros - IM_FMTARGS, IM_FMTLIST: Apply printf-style warnings to our formatting functions.
-#if !defined(IMGUI_USE_STB_SPRINTF) && defined(__MINGW32__)
+#if !defined(IMGUI_USE_STB_SPRINTF) && defined(__MINGW32__) && !defined(__clang__)
 #define IM_FMTARGS(FMT)             __attribute__((format(gnu_printf, FMT, FMT+1)))
 #define IM_FMTLIST(FMT)             __attribute__((format(gnu_printf, FMT, 0)))
 #elif !defined(IMGUI_USE_STB_SPRINTF) && (defined(__clang__) || defined(__GNUC__))