code cleanup for mark&sweep GC

tests/gc/gcleak.nim

@@ -12,7 +12,9 @@ type
 proc MakeObj(): TTestObj =
   result.x = "Hello"
 
-for i in 1 .. 100_000_000:
+for i in 1 .. 1_000_000:
+  when defined(gcMarkAndSweep):
+    GC_fullcollect()
   var obj = MakeObj()
   if getOccupiedMem() > 300_000: quit("still a leak!")
 #  echo GC_getstatistics()

tests/gc/gcleak2.nim

@@ -15,7 +15,9 @@ proc MakeObj(): TTestObj =
   result.s = @[1,2,3]
 
 proc inProc() = 
-  for i in 1 .. 100_000_000:
+  for i in 1 .. 1_000_000:
+    when defined(gcMarkAndSweep):
+      GC_fullcollect()
     var obj: TTestObj
     obj = MakeObj()
     if getOccupiedMem() > 300_000: quit("still a leak!")

tests/gc/weakrefs.nim

@@ -40,6 +40,8 @@ proc main =
   for i in 0 .. s.high:
     s[i] = register(create())
   # test that we have at least 80% unreachable weak objects by now:
+  when defined(gcMarkAndSweep):
+    GC_fullcollect()
   var unreachable = 0
   for i in 0 .. s.high:
     if access(s[i]) == nil: inc unreachable