tests/recursive_iternext.py: Make low-heap friendly.

tests/misc/recursive_iternext.py

 # This tests that recursion with iternext doesn't lead to segfault.
 
+try:
+    [0] * 10000
+    N = 1000
+except:
+    N = 100
+
 try:
     x = (1, 2)
-    for i in range(1000):
+    for i in range(N):
         x = enumerate(x)
     tuple(x)
 except RuntimeError:
@@ -10,7 +16,7 @@ except RuntimeError:
 
 try:
     x = (1, 2)
-    for i in range(1000):
+    for i in range(N):
         x = filter(None, x)
     tuple(x)
 except RuntimeError:
@@ -18,7 +24,7 @@ except RuntimeError:
 
 try:
     x = (1, 2)
-    for i in range(1000):
+    for i in range(N):
         x = map(max, x, ())
     tuple(x)
 except RuntimeError:
@@ -26,7 +32,7 @@ except RuntimeError:
 
 try:
     x = (1, 2)
-    for i in range(1000):
+    for i in range(N):
         x = zip(x)
     tuple(x)
 except RuntimeError: