[InstCombine] Add test for incorrect retention of Range attribute in fshl

Author: MaskRay

llvm/test/Transforms/InstCombine/fsh.ll

@@ -1068,3 +1068,18 @@ entry:
   %res = call <2 x i31> @llvm.fshl.v2i31(<2 x i31> %x, <2 x i31> zeroinitializer, <2 x i31>  %y)
   ret <2 x i31>  %res
 }
+
+define i8 @fshl_range_trunc(i1 %x) {
+; CHECK-LABEL: @fshl_range_trunc(
+; CHECK-NEXT:    [[ZEXT:%.*]] = zext i1 [[X:%.*]] to i32
+; CHECK-NEXT:    [[OR:%.*]] = or disjoint i32 [[ZEXT]], 126
+; CHECK-NEXT:    [[FSHL:%.*]] = call range(i32 -4, 2) i32 @llvm.fshl.i32(i32 [[OR]], i32 -2, i32 1)
+; CHECK-NEXT:    [[TR:%.*]] = trunc nuw i32 [[FSHL]] to i8
+; CHECK-NEXT:    ret i8 [[TR]]
+;
+  %zext = zext i1 %x to i32
+  %or = or disjoint i32 %zext, -2
+  %fshl = call range(i32 -4, 2) i32 @llvm.fshl.i32(i32 %or, i32 %or, i32 1)
+  %tr = trunc nsw i32 %fshl to i8
+  ret i8 %tr
+}