Filed issues/0138: `@const` (address-of a `::` comptime constant) lowers to `inttoptr (i64 <value> to ptr)` — segfaults on deref, invalid store for asm `-> @const`. Root cause in src/ir/lower/expr.zig .address_of (not asm). Marked CHECKPOINT-ASM Next step BLOCKED on 0138 for the output-to-const rejection item.