bite the bullet and make 'initStackBottom' a compilerproc

lib/system.nim

@@ -1680,11 +1680,11 @@ when not defined(EcmaScript) and not defined(NimrodVM):
   when not defined(boehmgc) and not defined(useMalloc):
     proc initAllocator() {.inline.}
 
-  when not defined(nogc):
-    proc initStackBottom() {.inline.} = 
-      # WARNING: This is very fragile! An array size of 8 does not work on my
-      # Linux 64bit system. Very strange, but we are at the will of GCC's 
-      # optimizer...
+  proc initStackBottom() {.inline, compilerproc.} =
+    # WARNING: This is very fragile! An array size of 8 does not work on my
+    # Linux 64bit system. Very strange, but we are at the will of GCC's 
+    # optimizer...
+    when defined(setStackBottom):
       var locals {.volatile.}: pointer
       locals = addr(locals)
       setStackBottom(locals)

lib/system/gc.nim

@@ -639,6 +639,7 @@ when not defined(useNimRtl):
     else:
       var a = cast[TAddress](theStackBottom) # and not PageMask - PageSize*2
       var b = cast[TAddress](gch.stackBottom)
+      #c_fprintf(c_stdout, "old: %p new: %p;\n",gch.stackBottom,theStackBottom)
       when stackIncreases:
         gch.stackBottom = cast[pointer](min(a, b))
       else: