Two sentences said more than was checked

The defconst divergence is dated from the history rather than asserted, and
the claim that it is the backends' only disagreement is gone — x86.ml has
unsupported paths of its own.

FIX.org

@@ -830,7 +830,8 @@ globals at all.
   form: a computed [defconst] would be guarded exactly like a computed
   [defvar]. The x86 backend does guard one; the LLVM backend refuses the
   program instead, because [Emit.const] has nowhere to run a computed value.
-  That divergence is older than this rule and is noted here rather than fixed.
+  That divergence predates the re-run rule — the refusal landed in 495629f and
+  the flags in 931cf86 — and is noted here rather than fixed.
 - If the language grows a [def]-style form that re-evaluates, that form
   recomputes on every run. None exists today and none was invented for this;
   the rule is written so that adding one is a new case and not a revision.

lib/emit.ml

@@ -3427,8 +3427,9 @@ let startup_sym = fname ".init-globals"
    over the form — nothing below asks [gconst]. A [defconst] with a computed
    initialiser would therefore be guarded here like any [defvar], and on the
    x86 backend it is. On this one it never arrives: [const] refuses a computed
-   [defconst] by name, because a constant has nowhere to run. The two backends
-   disagree about that program and only about that program.
+   [defconst] by name, because a constant has nowhere to run. So the two
+   backends disagree about that one program, and the disagreement is older
+   than this rule.
 
    So each computed initialiser guards itself with a flag of its own. Per
    global and not per startup function, because the rule belongs to the form: