Skeletal support for Python 3.7

Largely failing though.

uncompyle6/scanners/scanner37.py

@@ -0,0 +1,38 @@
+#  Copyright (c) 2016-2017 by Rocky Bernstein
+"""
+Python 3.7 bytecode decompiler scanner
+
+Does some additional massaging of xdis-disassembled instructions to
+make things easier for decompilation.
+
+This sets up opcodes Python's 3.6 and calls a generalized
+scanner routine for Python 3.
+"""
+
+from __future__ import print_function
+
+from uncompyle6.scanners.scanner3 import Scanner3
+
+# bytecode verification, verify(), uses JUMP_OPs from here
+from xdis.opcodes import opcode_36 as opc
+JUMP_OPs = map(lambda op: opc.opname[op], opc.hasjrel + opc.hasjabs)
+
+class Scanner37(Scanner3):
+
+    def __init__(self, show_asm=None):
+        Scanner3.__init__(self, 3.7, show_asm)
+        return
+    pass
+
+if __name__ == "__main__":
+    from uncompyle6 import PYTHON_VERSION
+    if PYTHON_VERSION == 3.7:
+        import inspect
+        co = inspect.currentframe().f_code
+        tokens, customize = Scanner37().ingest(co)
+        for t in tokens:
+            print(t.format())
+        pass
+    else:
+        print("Need to be Python 3.7 to demo; I am %s." %
+              PYTHON_VERSION)