fixes thread vars of non-global visibility

compiler/ccgexprs.nim

@@ -1976,7 +1976,8 @@ proc expr(p: BProc, n: PNode, d: var TLoc) =
     of skEnumField:
       putIntoDest(p, d, n.typ, rope(sym.position))
     of skVar, skForVar, skResult, skLet:
-      if sfGlobal in sym.flags: genVarPrototype(p.module, sym)
+      if {sfGlobal, sfThread} * sym.flags != {}:
+        genVarPrototype(p.module, sym)
       if sym.loc.r == nil or sym.loc.t == nil:
         #echo "FAILED FOR PRCO ", p.prc.name.s
         #echo renderTree(p.prc.ast, {renderIds})

compiler/cgen.nim

@@ -788,7 +788,7 @@ proc genProc(m: BModule, prc: PSym) =
           genProcAux(generatedHeader, prc)
 
 proc genVarPrototypeAux(m: BModule, sym: PSym) =
-  assert(sfGlobal in sym.flags)
+  #assert(sfGlobal in sym.flags)
   useHeader(m, sym)
   fillLoc(sym.loc, locGlobalVar, sym.typ, mangleName(sym), OnHeap)
   if (lfNoDecl in sym.loc.flags) or containsOrIncl(m.declaredThings, sym.id):