bugfix: c2nim: typedef unsigned char

lib/system.nim

@@ -1123,12 +1123,6 @@ proc isNil*(x: cstring): bool {.noSideEffect, magic: "IsNil".}
   ## Fast check whether `x` is nil. This is sometimes more efficient than
   ## ``== nil``.
 
-
-# Fixup some magic symbols here:
-#{.fixup_system.} 
-# This is an undocumented pragma that can only be used
-# once in the system module.
-
 proc `&` *[T](x, y: openArray[T]): seq[T] {.noSideEffect.} =
   newSeq(result, x.len + y.len)
   for i in 0..x.len-1:

lib/system/mmdisp.nim

@@ -136,6 +136,9 @@ elif defined(nogc):
   # object, because C does not support this operation... Even though every
   # possible implementation has to have a way to determine the object's size.
   # C just sucks.
+  when appType == "lib": 
+    {.warning: "nogc in a library context may not work".}
+  
   include "system/alloc"
 
   when false: