Make numerous improvements

- Python static hello world now 1.8mb
- Python static fully loaded now 10mb
- Python HTTPS client now uses MbedTLS
- Python REPL now completes import stmts
- Increase stack size for Python for now
- Begin synthesizing posixpath and ntpath
- Restore Python \N{UNICODE NAME} support
- Restore Python NFKD symbol normalization
- Add optimized code path for Intel SHA-NI
- Get more Python unit tests passing faster
- Get Python help() pagination working on NT
- Python hashlib now supports MbedTLS PBKDF2
- Make memcpy/memmove/memcmp/bcmp/etc. faster
- Add Mersenne Twister and Vigna to LIBC_RAND
- Provide privileged __printf() for error code
- Fix zipos opendir() so that it reports ENOTDIR
- Add basic chmod() implementation for Windows NT
- Add Cosmo's best functions to Python cosmo module
- Pin function trace indent depth to that of caller
- Show memory diagram on invalid access in MODE=dbg
- Differentiate stack overflow on crash in MODE=dbg
- Add stb_truetype and tools for analyzing font files
- Upgrade to UNICODE 13 and reduce its binary footprint
- COMPILE.COM now logs resource usage of build commands
- Start implementing basic poll() support on bare metal
- Set getauxval(AT_EXECFN) to GetModuleFileName() on NT
- Add descriptions to strerror() in non-TINY build modes
- Add COUNTBRANCH() macro to help with micro-optimizations
- Make error / backtrace / asan / memory code more unbreakable
- Add fast perfect C implementation of μ-Law and a-Law audio codecs
- Make strtol() functions consistent with other libc implementations
- Improve Linenoise implementation (see also github.com/jart/bestline)
- COMPILE.COM now suppresses stdout/stderr of successful build commands

third_party/python/Lib/posixpath.py

@@ -25,6 +25,8 @@ devnull = '/dev/null'
 import os
 import sys
 import stat
+import cosmo
+import ntpath
 import genericpath
 from genericpath import *
 
@@ -64,6 +66,8 @@ def normcase(s):
 
 def isabs(s):
     """Test whether a path is absolute"""
+    if cosmo.kernel == 'nt' and '\\' in s:
+        return ntpath.isabs(s)
     s = os.fspath(s)
     sep = _get_sep(s)
     return s.startswith(sep)
@@ -78,6 +82,8 @@ def join(a, *p):
     If any component is an absolute path, all previous path components
     will be discarded.  An empty last part will result in a path that
     ends with a separator."""
+    if cosmo.kernel == 'nt' and '\\' in a:
+        return ntpath.join(a, *p)
     a = os.fspath(a)
     sep = _get_sep(a)
     path = a
@@ -233,6 +239,8 @@ def ismount(path):
 def expanduser(path):
     """Expand ~ and ~user constructions.  If user or $HOME is unknown,
     do nothing."""
+    if cosmo.kernel == 'nt' and '\\' in path:
+        return ntpath.expanduser(path)
     path = os.fspath(path)
     if isinstance(path, bytes):
         tilde = b'~'