index: use PyMem_Free() to free nodeetree instance As Yuya pointed out in the review of D4108, PyMem_Malloc() and PyMem_Free() should be paired. IIUC, PyMem_Malloc() may use a different allocator than malloc(), so using free() with a pointer from PyMem_Malloc() may be very wrong. Differential Revision: https://phab.mercurial-scm.org/D4152