[LV] Extend FIXME in test add in 91ee1e3.

Author: fhahn

llvm/test/Transforms/LoopVectorize/runtime-check-small-clamped-bounds.ll

@@ -1,10 +1,13 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -loop-vectorize -force-vector-width=2 -S %s | FileCheck %s
 
-; Tests where the indices of some accesses are clamped to a small value.
-; FIXME: At the moment, the runtime checks require that the indices do not wrap.
-;        The clamped indices do wrap, so the vector loops are dead at the
-;        moment.
+; Tests where the indices of some accesses are clamped to a small range.
+
+; FIXME: At the moment, the runtime checks require that the indices do not wrap
+;        and runtime checks are emitted to ensure that. The clamped indices do
+;        wrap, so the vector loops are dead at the moment. But it is still
+;        possible to compute the bounds of the accesses and generate proper
+;        runtime checks.
 
 ; The relevant bounds for %gep.A are [%A, %A+4).
 define void @load_clamped_index(i32* %A, i32* %B, i32 %N) {