int_big_to_small: Bifurcate test using small_int_max.

Different results are needed for different integer sizes.

Signed-off-by: Jeff Epler <jepler@gmail.com>

tests/basics/int_big_to_small.py

@@ -5,6 +5,16 @@ except:
     print("SKIP")
     raise SystemExit
 
+micropython.heap_lock()
+try:
+    k = (1 << 29)
+    k = k + 20
+except MemoryError:
+    micropython.heap_unlock()
+    print("SKIP")
+    raise SystemExit
+micropython.heap_unlock()
+
 # All less than small int max.
 for d in (0, 27, 1<<29, -1861, -(1<<29)):
     i = 1<<70

tests/basics/int_big_to_small_int29.py

@@ -0,0 +1,32 @@
+try:
+    import micropython
+    micropython.heap_lock
+except:
+    print("SKIP")
+    raise SystemExit
+
+micropython.heap_lock()
+try:
+    k = (1 << 28)
+    k = k + 20
+except MemoryError:
+    micropython.heap_unlock()
+    print("SKIP")
+    raise SystemExit
+micropython.heap_unlock()
+
+# All less than small int max.
+for d in (0, 27, 1<<28, -1861, -(1<<28)):
+    i = 1<<70
+    print(i)
+    j = (1<<70) + d
+    print(j)
+    # k should now be a small int.
+    k = j - i
+    print(k)
+
+    # Now verify that working with k doesn't allocate (i.e. it's a small int).
+    micropython.heap_lock()
+    print(k + 20)
+    print(k // 20)
+    micropython.heap_unlock()

tests/basics/int_big_to_small_int29.py.exp

@@ -0,0 +1,25 @@
+1180591620717411303424
+1180591620717411303424
+0
+20
+0
+1180591620717411303424
+1180591620717411303451
+27
+47
+1
+1180591620717411303424
+1180591620717679738880
+268435456
+268435476
+13421772
+1180591620717411303424
+1180591620717411301563
+-1861
+-1841
+-94
+1180591620717411303424
+1180591620717142867968
+-268435456
+-268435436
+-13421773