Moves EVAL as method back to Cool

Also eliminates implementation details from EVAL. Closes #2822

doc/Type/Cool.pod6

@@ -142,6 +142,17 @@ imaginary part negated).
 
     say (1+2i).conj;        # OUTPUT: «1-2i␤»
 
+=head2 routine EVAL
+
+Defined as:
+
+=for code :method
+    method EVAL(*%_)
+
+It calls the L<subroutine form|/type/independent-routines#sub_mkdir> with the
+invocant as the first argument, C<$code>, passing along named args, if any.
+
+
 =head2 routine sqrt
 
 Defined as:

doc/Type/independent-routines.pod6

@@ -12,23 +12,18 @@ actually attached to any particular class or role.
 Defined as:
 
 =begin code :method
-method EVAL(*%_)
-=end code
-=begin code :method
-proto sub EVAL($code is copy where Blob|Cool|Callable, Str() :$lang = 'perl6',
+proto sub EVAL($code where Blob|Cool|Callable, Str() :$lang = 'perl6',
                 PseudoStash :$context, *%n)
 =end code
 =begin code :method
 multi sub EVAL($code, Str :$lang where { ($lang // '') eq 'Perl5' },
                 PseudoStash :$context)
 =end code
 
-If it is invoked as a method, it calls the subroutine form with
-invocant as the first argument, C<$code>, passing along named args, if any; this
-coerces L<Cool|/type/Cool> C<$code> to L<Str|/type/Str>. If C<$code> is a
-L<Blob|/type/Blob>, it'll be processed using the same encoding as the C<$lang>
-compiler would: for C<perl6> C<$lang>, uses C<utf-8>; for C<Perl5>, processes
-using the same rules as C<perl>.
+This routine coerces L<Cool|/type/Cool> C<$code> to L<Str|/type/Str>. If
+C<$code> is a L<Blob|/type/Blob>, it'll be processed using the same encoding as
+the C<$lang> compiler would: for C<perl6> C<$lang>, uses C<utf-8>; for C<Perl5>,
+processes using the same rules as C<perl>.
 
 This works as-is with a literal string parameter. More complex input,
 such as a variable or string with embedded code, is illegal by default.