[llvm] Add enum iteration to Sequence

This patch allows iterating typed enum via the ADT/Sequence utility.

It also changes the original design to better separate concerns:
 - `StrongInt` only deals with safe `intmax_t` operations,
 - `SafeIntIterator` presents the iterator and reverse iterator
 interface but only deals with safe `StrongInt` internally.
 - `iota_range` only deals with `SafeIntIterator` internally.

 This design ensures that operations are always valid. In particular,
 "Out of bounds" assertions fire when:
  - the `value_type` is not representable as an `intmax_t`
  - iterator operations make internal computation underflow/overflow
  - the internal representation cannot be converted back to `value_type`

Differential Revision: https://reviews.llvm.org/D106279

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/unittests/IR/ConstantRangeTest.cpp b/llvm/unittests/IR/ConstantRangeTest.cpp
index f8816e4..8eca261 100644
--- a/llvm/unittests/IR/ConstantRangeTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeTest.cpp
@@ -1551,9 +1551,9 @@ void ICmpTestImpl(CmpInst::Predicate Pred) {
 }
 
 TEST(ConstantRange, ICmp) {
-  for (auto Pred : seq<unsigned>(CmpInst::Predicate::FIRST_ICMP_PREDICATE,
-                                 1 + CmpInst::Predicate::LAST_ICMP_PREDICATE))
-    ICmpTestImpl((CmpInst::Predicate)Pred);
+  for (auto Pred : seq_inclusive(CmpInst::Predicate::FIRST_ICMP_PREDICATE,
+                                 CmpInst::Predicate::LAST_ICMP_PREDICATE))
+    ICmpTestImpl(Pred);
 }
 
 TEST(ConstantRange, MakeGuaranteedNoWrapRegion) {