Handle different enum sizes in reprAux (#5207)

tests/system/tenum_array_repr.nim

@@ -0,0 +1,25 @@
+discard """
+  output: '''
+1
+[a, b]
+
+2
+[c, d]
+
+4
+[e, f]'''
+"""
+
+# issue 5045
+
+type size1 = enum a, b
+echo sizeof(size1)
+echo repr([a, b])
+
+type size2 = enum c=0, d=20000
+echo sizeof(size2)
+echo repr([c, d])
+
+type size4 = enum e=0, f=2000000000
+echo sizeof(size4)
+echo repr([e, f])