refact(Lib/sys): split into sys_impl/; add n_sys

Author: litlighilit

src/pylib/Lib/n_sys.nim

@@ -0,0 +1,21 @@
+
+import std/options
+import ../private/trans_imp
+
+import ./sys_impl/[
+  genplatform, geninfos, genargs
+]
+template asis[T](x: T): T = x
+genPlatform(asis)
+genInfos(asis, none(string))
+template append(x: seq, y) = x.add y
+genArgs string, seq, asis, asis, newSeqOfCap
+
+impExp sys_impl,
+  fenvs,
+  stdio,
+  exits,
+  getencodings,
+  sizes
+
+