Issue2564: Prevent a hang in "import test.autotest", which runs the entire test
suite as a side-effect of importing the module.

- in test_capi, a thread tried to import other modules
- re.compile() imported sre_parse again on every call.
diff --git a/Lib/sre_compile.py b/Lib/sre_compile.py
index 22ab2fd..65d2ccf 100644
--- a/Lib/sre_compile.py
+++ b/Lib/sre_compile.py
@@ -11,7 +11,7 @@
 """Internal support module for sre"""
 
 import _sre, sys
-
+import sre_parse
 from sre_constants import *
 
 assert _sre.MAGIC == MAGIC, "SRE module mismatch"
@@ -502,7 +502,6 @@
     # internal: convert pattern list to internal format
 
     if isstring(p):
-        import sre_parse
         pattern = p
         p = sre_parse.parse(p, flags)
     else: