Merge 3.5 (_tracemalloc)

diff --cc Modules/_tracemalloc.c
index 2eb4dcad444f18196e1c1d5f19bc9176de23ff19,fd520f3259c36455ff1e199f8ead9c7f267b769b..1940af429adfa12f1a19bf2e1135d5fbf33dc458
--- 1/Modules/_tracemalloc.c
--- 2/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@@ -65,10 -65,8 +65,10 @@@ __attribute__((packed)
  _declspec(align(4))
  #endif
  {
 +    /* filename cannot be NULL: "<unknown>" is used if the Python frame
 +       filename is NULL */
      PyObject *filename;
-     int lineno;
+     unsigned int lineno;
  } frame_t;
  
  typedef struct {