Add greenlet support

python3/Makefile

@@ -42,17 +42,18 @@ build/hostpython: | dl/$(TARBALL)
 	mv build/python build/hostpython
 
 build/Parser/hostpgen: build/hostpython
-	mv build/Parser/pgen build/Parser/hostpgen
+	cp build/Parser/pgen build/Parser/hostpgen
 
 build/Programs/host_freeze_importlib: build/Parser/hostpgen
-	mv build/Programs/_freeze_importlib build/Programs/host_freeze_importlib
+	cp build/Programs/_freeze_importlib build/Programs/host_freeze_importlib
 
 build/configure: build/Programs/host_freeze_importlib
 	(cd build; make distclean)
 
 build/stamp_patch: build/configure patches/*
 	cp config.site build/
 	(cd build && ../../scripts/apply-patches.sh ./ ../patches/*)
+	cp -R files/* build/Modules/
 	touch $@
 
 build/Makefile: build/stamp_patch

python3/README.md

@@ -21,6 +21,9 @@ but not everything. If you have an ImportError while trying to import a module
 you feel should exist, please examine the `build/Modules/Setup` file to make
 sure it is compiled into Python.
 
+[Greenlets](https://greenlet.readthedocs.io/en/latest/) support is built into this
+package. Greenlets are like coroutines. The example script includes greenlets so
+you can see how they operate.
 
 Instructions
 ============

python3/examples/main.py

@@ -9,6 +9,8 @@
 import json
 import csv
 
+from greenlet import greenlet
+
 
 def hello_world():
     print("\n" * 4)
@@ -27,6 +29,21 @@ def hello_world():
 
     print("\n" * 2)
 
+
+def test1():
+    print(12)
+    gr2.switch()
+    print(34)
+
+def test2():
+    print(56)
+    gr1.switch()
+    print(78)
+
+
+gr1 = greenlet(test1)
+gr2 = greenlet(test2)
+
 if __name__ == '__main__':
     hello_world()
-
+    gr1.switch()