Decentralize Python native module linkage

We can now link even smaller Python binaries. For example, the hello.com
program in the Python build directory is a compiled linked executable of
hello.py which just prints hello world. Using decentralized sections, we
can make that binary 1.9mb in size (noting that python.com is 6.3 megs!)

This works for nontrivial programs too. For example, say we want an APE
binary that's equivalent to python.com -m http.server. Our makefile now
builds such a binary using the new launcher and it's only 3.2mb in size
since Python sources get turned into ELF objects, which tell our linker
that we need things like native hashing algorithm code.

third_party/python/Lib/shutil.py

@@ -626,7 +626,10 @@ def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
         raise ValueError("bad value for 'compress', or compression format not "
                          "supported : {0}".format(compress))
 
-    import tarfile  # late import for breaking circular dependency
+    try:
+        import tarfile
+    except ImportError:
+        raise
 
     compress_ext = '.' + tar_compression if compress else ''
     archive_name = base_name + '.tar' + compress_ext
@@ -669,7 +672,10 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
     The output zip file will be named 'base_name' + ".zip".  Returns the
     name of the output zip file.
     """
-    import zipfile  # late import for breaking circular dependency
+    try:
+        import zipfile
+    except ImportError:
+        raise
 
     zip_filename = base_name + ".zip"
     archive_dir = os.path.dirname(base_name)
@@ -877,7 +883,10 @@ def _ensure_directory(path):
 def _unpack_zipfile(filename, extract_dir):
     """Unpack zip `filename` to `extract_dir`
     """
-    import zipfile  # late import for breaking circular dependency
+    try:
+        import zipfile
+    except ImportError:
+        raise
 
     if not zipfile.is_zipfile(filename):
         raise ReadError("%s is not a zip file" % filename)
@@ -911,7 +920,10 @@ def _unpack_zipfile(filename, extract_dir):
 def _unpack_tarfile(filename, extract_dir):
     """Unpack tar/tar.gz/tar.bz2/tar.xz `filename` to `extract_dir`
     """
-    import tarfile  # late import for breaking circular dependency
+    try:
+        import tarfile
+    except ImportError:
+        raise
     try:
         tarobj = tarfile.open(filename)
     except tarfile.TarError:
@@ -1003,22 +1015,6 @@ if hasattr(os, 'statvfs'):
         used = (st.f_blocks - st.f_bfree) * st.f_frsize
         return _ntuple_diskusage(total, used, free)
 
-elif os.name == 'nt':
-
-    import nt
-    __all__.append('disk_usage')
-    _ntuple_diskusage = collections.namedtuple('usage', 'total used free')
-
-    def disk_usage(path):
-        """Return disk usage statistics about the given path.
-
-        Returned values is a named tuple with attributes 'total', 'used' and
-        'free', which are the amount of total, used and free space, in bytes.
-        """
-        total, free = nt._getdiskusage(path)
-        used = total - free
-        return _ntuple_diskusage(total, used, free)
-
 
 def chown(path, user=None, group=None):
     """Change owner user and group of the given path.