[ConstraintElim] Add pre-commit tests. NFC.

Author: dtcxzyw

llvm/test/Transforms/ConstraintElimination/or-implied-by-operands.ll

@@ -307,3 +307,18 @@ entry:
   %or = select i1 %cmp.eq, i1 true, i1 %cmp.eq.1
   ret i1 %or
 }
+
+define i1 @test_or_disjoint_set_operand(i8 %x) {
+; CHECK-LABEL: @test_or_disjoint_set_operand(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i8 [[X:%.*]], 1
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ne i8 [[X]], 0
+; CHECK-NEXT:    [[OR:%.*]] = or disjoint i1 [[CMP2]], true
+; CHECK-NEXT:    ret i1 [[OR]]
+;
+entry:
+  %cmp1 = icmp slt i8 %x, 1
+  %cmp2 = icmp ne i8 %x, 0
+  %or = or disjoint i1 %cmp2, %cmp1
+  ret i1 %or
+}