Use local array instead of slice pool inside stack.Trace.

Author: ChrisHines

stack.go

@@ -224,9 +224,9 @@ func Trace() CallStack {
 		sigpanic = findSigpanic()
 	})
 
-	pcs := getUintptrs()
+	var pcs [512]uintptr
 
-	n := runtime.Callers(2, pcs)
+	n := runtime.Callers(2, pcs[:])
 	cs := make([]Call, n)
 
 	for i, pc := range pcs[:n] {
@@ -240,8 +240,6 @@ func Trace() CallStack {
 		}
 	}
 
-	putUintptrs(pcs)
-
 	return cs
 }