build(python): simplify rpycdec vendor layout

third_party/python/rpycdec/src/renpy/pyanalysis.py

@@ -0,0 +1,25 @@
+import ast
+
+# Three levels of constness.
+GLOBAL_CONST = 2  # Expressions that are const everywhere.
+LOCAL_CONST = 1  # Expressions that are const with regard to a screen + parameters.
+NOT_CONST = 0  # Expressions that are not const.
+
+
+class Control(object):
+    pass
+
+
+class Analysis(object):
+    pass
+
+
+class PyAnalysis(ast.NodeVisitor):
+    pass
+
+
+class CompilerCache(object):
+    pass
+
+
+ccache = CompilerCache()