bpo-23224: Fix segfaults and multiple leaks in the lzma and bz2 modules (GH-7822)

lzma.LZMADecompressor and bz2.BZ2Decompressor objects caused
segfaults when their `__init__()` methods were not called.

lzma.LZMADecompressor, lzma.LZMACompressor, bz2.BZ2Compressor,
and bz2.BZ2Decompressor objects would leak locks and internal buffers
when their `__init__()` methods were called multiple times.


https://bugs.python.org/issue23224