Use BLDLIBRARY to build extension modules. Fixes #504252.
2.2.1 candidate.
diff --git a/Makefile.pre.in b/Makefile.pre.in
index f4eb01d..a966931 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -303,8 +303,8 @@
 # Build the shared modules
 sharedmods: $(BUILDPYTHON)
 	case $$MAKEFLAGS in \
-	*-s*) CC='$(CC)' LDSHARED='$(LDSHARED)' OPT='$(OPT)' ./$(BUILDPYTHON) -E $(srcdir)/setup.py -q build;; \
-	*) CC='$(CC)' LDSHARED='$(LDSHARED)' OPT='$(OPT)' ./$(BUILDPYTHON) -E $(srcdir)/setup.py build;; \
+	*-s*) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' ./$(BUILDPYTHON) -E $(srcdir)/setup.py -q build;; \
+	*) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' ./$(BUILDPYTHON) -E $(srcdir)/setup.py build;; \
 	esac
 
 # buildno should really depend on something like LIBRARY_SRC