add static assertions in the generated code about platform-related assumptions

compiler/cgen.nim

@@ -40,15 +40,7 @@ proc addForwardedProc(m: BModule, prc: PSym) =
 
 proc findPendingModule(m: BModule, s: PSym): BModule = 
   var ms = getModule(s)
-  if ms.id == m.module.id: return m
-  for i in countup(0, high(gModules)): 
-    result = gModules[i]
-    if result.module.id == ms.id: return 
-  # else we found no pending module: This can happen for procs that are in
-  # a module that is already closed. This is fine, don't generate code for
-  # it then:
-  result = nil
-  #InternalError(s.info, "no pending module found for: " & s.name.s)
+  result = gModules[ms.position]
 
 proc emitLazily(s: PSym): bool {.inline.} =
   result = optDeadCodeElim in gGlobalOptions or
@@ -1139,6 +1131,11 @@ proc writeModule(m: BModule, pending: bool) =
     addFileToCompile(cfilenoext)
   addFileToLink(cfilenoext)
 
+proc genPlatformAsserts(m: BModule) =
+  appf(m.s[cfsForwardTypes],
+    "typedef assert_numbits[sizeof(NI) == sizeof(void*) &&" &
+                           "NIM_INTBITS == sizeof(NI)*8 ? 1 : -1];$N")
+
 proc myClose(b: PPassContext, n: PNode): PNode = 
   result = n
   if b == nil or passes.skipCodegen(n): return 
@@ -1152,6 +1149,7 @@ proc myClose(b: PPassContext, n: PNode): PNode =
   if sfMainModule in m.module.flags: 
     var disp = generateMethodDispatchers()
     for i in 0..sonsLen(disp)-1: genProcAux(m, disp.sons[i].sym)
+    genPlatformAsserts(m)
     genMainProc(m) 
     # we need to process the transitive closure because recursive module
     # deps are allowed (and the system module is processed in the wrong