[Docs] Fix scoped noalias example

[anemet]

Summary

As far as I understand the entire point of this example is to show that
if noalias is not a superset/equal to the alias.scope list on a scope
domain then load could reference locations that the store is not known
to not-alias i.e may alias.

BTW, it would probably make sense to describe that independent domains
are considered non-alias. Different roots are describe under TBAA but
not here and the behavior here AFAIK is the opposite.

[hfinkel]

LGTM. (Ack, yes, you're right: it must be may alias to match the comment).

docs/LangRef.rst

.. code-block:: llvm
     %0 = load float, float* %c, align 4, !alias.scope !5
     store float %0, float* %arrayidx.i, align 4, !noalias !5
 
     ; These two instructions also don't alias (for domain !1, the set of scopes
     ; in the !alias.scope equals that in the !noalias list):
     %2 = load float, float* %c, align 4, !alias.scope !5
     store float %2, float* %arrayidx.i2, align 4, !noalias !6
 
-    ; These two instructions don't alias (for domain !0, the set of scopes in
+    ; These two instructions may alias (for domain !0, the set of scopes in
     ; the !noalias list is not a superset of, or equal to, the scopes in the
     ; !alias.scope list):
     %2 = load float, float* %c, align 4, !alias.scope !6
     store float %0, float* %arrayidx.i, align 4, !noalias !7
 
 '``fpmath``' Metadata
 ^^^^^^^^^^^^^^^^^^^^^