GC with realtime support

tests/gc/gcbench.nim

@@ -161,5 +161,8 @@ proc main() =
   var elapsed = epochTime() - t
   PrintDiagnostics()
   echo("Completed in " & $elapsed & "ms. Success!")
+
+when defined(GC_setMaxPause):
+  GC_setMaxPause 2_000
 
 main()

tests/gc/gcleak.nim

@@ -2,6 +2,9 @@ discard """
   outputsub: "no leak: "
 """
 
+when defined(GC_setMaxPause):
+  GC_setMaxPause 2_000
+
 type
   TTestObj = object of TObject
     x: string

tests/gc/gcleak2.nim

@@ -2,6 +2,9 @@ discard """
   outputsub: "no leak: "
 """
 
+when defined(GC_setMaxPause):
+  GC_setMaxPause 2_000
+
 type
   TTestObj = object of TObject
     x: string

tests/gc/gcleak3.nim

@@ -2,6 +2,9 @@ discard """
   outputsub: "no leak: "
 """
 
+when defined(GC_setMaxPause):
+  GC_setMaxPause 2_000
+
 type
   TSomething = object
     s: string