Remove note about the compiler not checking for two kinds of illegal

imports.  It checks for them now.

Doc/ref/ref6.tex

@@ -576,11 +576,6 @@ The \keyword{from} form with \samp{*} may only occur in a module scope.
 \kwindex{from}
 \stindex{from}
 
-(The current implementation does not enforce the latter two
-restrictions, but programs should not abuse this freedom, as future
-implementations may enforce them or silently change the meaning of the
-program.)
-
 \strong{Hierarchical module names:}\indexiii{hierarchical}{module}{names}
 when the module names contains one or more dots, the module search
 path is carried out differently.  The sequence of identifiers up to