lang: inline for element form over packs — multi-iterable parity

src/ir/lower/pack.zig

@@ -147,7 +147,7 @@ pub fn diagPackAsValue(self: *Lowering, name: []const u8, span: ast.Span, kind:
             .storage => d.addHelpFmt(id, span, null, "to store it, materialize a tuple: `(..{s})`", .{name}),
             .call_arg => d.addHelpFmt(id, span, null, "to pass it to a `[]Any`/`[]P` parameter, materialize it with `xx {s}`", .{name}),
             .return_value => d.addHelpFmt(id, span, null, "to return it, return a tuple `(..{s})` and make the return type that tuple", .{name}),
-            .runtime_iter => d.addHelpFmt(id, span, null, "to iterate at comptime use `inline for 0..{s}.len (i)`; for a runtime loop declare it as `..{s}: []P` (a protocol slice) instead of a pack", .{ name, name }),
+            .runtime_iter => d.addHelpFmt(id, span, null, "to iterate at comptime use `inline for {s} (x)` (or `inline for 0..{s}.len (i)` for the index); for a runtime loop declare it as `..{s}: []P` (a protocol slice) instead of a pack", .{ name, name, name }),
             .generic => d.addHelpFmt(id, span, null, "materialize a tuple `(..{s})` to store it, or `xx {s}` to convert it to an expected `[]Any`/`[]P` slice", .{ name, name }),
         }
     }