Issue #16840. Turn off bignum support in tkinter with with Tcl earlier than 8.5.8
(tclTomMath.h was broken) and non-final Tcl 8.6.
Removed TK_VERSION_HEX.
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 3f58353..4d61bb2 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -52,11 +52,12 @@
 
 #include "tkinter.h"
 
-#if TK_VERSION_HEX < 0x08040002
+#if TK_HEX_VERSION < 0x08040200
 #error "Tk older than 8.4 not supported"
 #endif
 
-#if TK_VERSION_HEX >= 0x08050002
+#if TK_HEX_VERSION >= 0x08050208 && TK_HEX_VERSION < 0x08060000 || \
+    TK_HEX_VERSION >= 0x08060200
 #define HAVE_LIBTOMMAMTH
 #include <tclTomMath.h>
 #endif
@@ -1227,7 +1228,7 @@
             Tcl_GetCharLength(value));
     }
 
-#if TK_VERSION_HEX >= 0x08050000
+#if TK_HEX_VERSION >= 0x08050000
     if (app->BooleanType == NULL &&
         strcmp(value->typePtr->name, "booleanString") == 0) {
         /* booleanString type is not registered in Tcl */