Enhancements to a comment in sqliteInt.h.  No changes to code.

FossilOrigin-Name: 5446ae64d7f92444ca40aae2108015d1d77bc03f
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 2e1adb8..338a573 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1382,7 +1382,8 @@
 
 /*
 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
-** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
+** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  And
+** SQLITE_FUNC_CONSTANT must be the same as SQLITE_DETERMINISTIC.  There
 ** are assert() statements in the code to verify this.
 */
 #define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */