Begin incorporating Python unit tests into build

We now build a separate APE binary for each test so they can run in
parallel. We've got 148 tests running fast and stable so far.

third_party/python/Lib/hashlib.py

@@ -11,7 +11,10 @@ new(name, data=b'', **kwargs) - returns a new hash object implementing the
 Named constructor functions are also available, these are faster
 than using new(name):
 
-md5(), sha1(), sha224(), sha256(), sha384(), sha512(), and blake2b256().
+md5(), sha1(), sha224(), sha256(), sha384(), sha512(), sha3_224(),
+sha3_256(), sha3_384(), sha3_512(), shake_128(), shake_256(), and
+finally blake2b256() which is an Actually Portable Python feature
+courtesy of the BoringSSL project at Google, and we thank ARM too
 
 More algorithms may be available on your platform but the above are guaranteed
 to exist.  See the algorithms_guaranteed and algorithms_available attributes
@@ -52,10 +55,22 @@ More condensed:
 
 """
 
+# import _hashlib as _prevent_recursive_loading
+# del _prevent_recursive_loading
+# if __name__ == 'PYOBJ.COM': import _sha3, _hashlib  # static-only
+
+if __name__ == 'PYOBJ.COM':
+    import _md5
+    import _sha1
+    import _sha256
+    import _sha512
+
 # This tuple and __get_builtin_constructor() must be modified if a new
 # always available algorithm is added.
 __always_supported = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512',
-                      'blake2b256')
+                      # 'sha3_224',  'sha3_256',  'sha3_384',
+                      # 'sha3_512', 'shake_128', 'shake_256'
+                      )
 
 algorithms_guaranteed = set(__always_supported)
 algorithms_available = set(__always_supported)
@@ -70,12 +85,23 @@ def __get_builtin_constructor(name):
     constructor = cache.get(name)
     if constructor is not None:
         return constructor
-    if name in ('MD5', 'md5'):
-        import _md5
-        cache['MD5'] = cache['md5'] = _md5.md5
-    elif name in {'sha3_224', 'sha3_256', 'sha3_384', 'sha3_512',
-                  'shake_128', 'shake_256'}:
-        try:
+    try:
+        if name in ('SHA1', 'sha1'):
+            import _sha1
+            cache['SHA1'] = cache['sha1'] = _sha1.sha1
+        elif name in ('MD5', 'md5'):
+            import _md5
+            cache['MD5'] = cache['md5'] = _md5.md5
+        elif name in ('SHA256', 'sha256', 'SHA224', 'sha224'):
+            import _sha256
+            cache['SHA224'] = cache['sha224'] = _sha256.sha224
+            cache['SHA256'] = cache['sha256'] = _sha256.sha256
+        elif name in ('SHA512', 'sha512', 'SHA384', 'sha384'):
+            import _sha512
+            cache['SHA384'] = cache['sha384'] = _sha512.sha384
+            cache['SHA512'] = cache['sha512'] = _sha512.sha512
+        elif name in {'sha3_224', 'sha3_256', 'sha3_384', 'sha3_512',
+                      'shake_128', 'shake_256'}:
             import _sha3
             cache['sha3_224'] = _sha3.sha3_224
             cache['sha3_256'] = _sha3.sha3_256
@@ -83,11 +109,13 @@ def __get_builtin_constructor(name):
             cache['sha3_512'] = _sha3.sha3_512
             cache['shake_128'] = _sha3.shake_128
             cache['shake_256'] = _sha3.shake_256
-        except ImportError:
-            raise ValueError('unsupported hash type ' + name)
+    except ImportError:
+        pass  # no extension module, this hash is unsupported.
+
     constructor = cache.get(name)
     if constructor is not None:
         return constructor
+
     raise ValueError('unsupported hash type ' + name)
 
 
@@ -125,11 +153,15 @@ def __hash_new(name, data=b'', **kwargs):
         return __get_builtin_constructor(name)(data)
 
 
-import _hashlib
-new = __hash_new
-__get_hash = __get_mbedtls_constructor
-algorithms_available = algorithms_available.union(
-        _hashlib.mbedtls_md_meth_names)
+try:
+    import _hashlib
+    new = __hash_new
+    __get_hash = __get_mbedtls_constructor
+    algorithms_available = algorithms_available.union(
+            _hashlib.mbedtls_md_meth_names)
+except ImportError as e:
+    new = __py_new
+    __get_hash = __get_builtin_constructor
 
 try:
     # Mbedtls's PKCS5_PBKDF2_HMAC requires Mbedtls 1.0+ with HMAC and SHA
@@ -201,13 +233,20 @@ try:
 except ImportError:
     pass
 
+
 md5 = __get_hash('md5')
 sha1 = __get_hash('sha1')
 sha224 = __get_hash('sha224')
 sha256 = __get_hash('sha256')
 sha384 = __get_hash('sha384')
 sha512 = __get_hash('sha512')
-blake2b256 = __get_hash('blake2b256')
+# sha3_224 = __get_hash('sha3_224')
+# sha3_256 = __get_hash('sha3_256')
+# sha3_384 = __get_hash('sha3_384')
+# sha3_512 = __get_hash('sha3_512')
+# shake_128 = __get_hash('shake_128')
+# shake_256 = __get_hash('shake_256')
+
 
 # Cleanup locals()
 del __always_supported, __get_hash