Fixes issue26307: The profile-opt build now applys PGO to the built-in modules.

Makefile.pre.in

@@ -1393,7 +1393,7 @@ clean: pycremoval
 	find build -name 'fficonfig.h' -exec rm -f {} ';' || true
 	find build -name 'fficonfig.py' -exec rm -f {} ';' || true
 	-rm -f Lib/lib2to3/*Grammar*.pickle
-	-rm -rf build
+	-find build -type f -a ! -name '*.gc??' -exec rm -f {} ';'
 
 profile-removal:
 	find . -name '*.gc??' -exec rm -f {} ';'

Misc/NEWS

@@ -10,6 +10,8 @@ What's New in Python 2.7.13?
 Core and Builtins
 -----------------
 
+- Issue #26307: The profile-opt build now applys PGO to the built-in modules.
+
 - Issue #27870: A left shift of zero by a large integer no longer attempts
   to allocate large amounts of memory.