fixes #14616 [backport:1.2] (#15109)

compiler/semmagic.nim

@@ -564,5 +564,9 @@ proc magicsAfterOverloadResolution(c: PContext, n: PNode,
     if not checkIsolate(n[1]):
       localError(c.config, n.info, "expression cannot be isolated: " & $n[1])
     result = n
+  of mPred:
+    if n[1].typ.skipTypes(abstractInst).kind in {tyUInt..tyUInt64}:
+      n[0].sym.magic = mSubU
+    result = n
   else:
     result = n

tests/misc/tunsignedconv.nim

@@ -59,3 +59,13 @@ discard $(x1,)
 # bug #13698
 let n: csize = 1 # xxx should that be csize_t or is that essential here?
 doAssert $n.int32 == "1"
+
+# bug #14616
+
+let limit = 1'u64
+
+let rangeVar = 0'u64 ..< limit
+
+doAssert repr(rangeVar) == """[a = 0,
+b = 0]
+"""