Issue #1602133: 'environ' is not really available with shared libraries on OSX

There already was a workaround for this for framework builds on OSX,
this changeset enables the same workaround for shared libraries.

Closes #1602133
diff --git a/Misc/NEWS b/Misc/NEWS
index 1f6875d..3a4a6cc 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -181,6 +181,9 @@
 - Issue #13521: dict.setdefault() now does only one lookup for the given key,
   making it "atomic" for many purposes.  Patch by Filip GruszczyƄski.
 
+- Issue #1602133: on Mac OS X a shared library build (``--enable-shared``)
+  now fills the ``os.environ`` variable correctly.
+
 - Issue #10538: When using the "s*" code with PyArg_ParseTuple() to fill a
   Py_buffer structure with data from an object supporting only the old
   PyBuffer interface, a reference to the source objects is now properly added