[IMM32] Rewrite ImmIsIME (Retry) (#3803)

- Rewrite ImmIsIME function.
- Fix enum IMEINFOEXCLASS.
CORE-11700

dll/win32/imm32/imm.c

@@ -2200,10 +2200,16 @@ HKL WINAPI ImmInstallIMEW(
  */
 BOOL WINAPI ImmIsIME(HKL hKL)
 {
+#ifdef __REACTOS__
+    IMEINFOEX info;
+    TRACE("ImmIsIME(%p)\n", hKL);
+    return !!ImmGetImeInfoEx(&info, ImeInfoExImeWindow, &hKL);
+#else
     ImmHkl *ptr;
     TRACE("(%p):\n", hKL);
     ptr = IMM_GetImmHkl(hKL);
     return (ptr && ptr->hIME);
+#endif
 }
 
 /***********************************************************************

win32ss/include/ntuser.h

@@ -1179,6 +1179,7 @@ typedef struct tagIMEINFOEX
 typedef enum IMEINFOEXCLASS
 {
     ImeInfoExKeyboardLayout,
+    ImeInfoExImeWindow,
     ImeInfoExImeFileName
 } IMEINFOEXCLASS;