Adds `local.exp` to CLEANFILES

With #315, #316, #317, #318 and this patch, running
```
AM_DISTCHECK_CONFIGURE_FLAGS=--disable-docs make distcheck
```
should complete successfully.

diff --git a/Makefile.am b/Makefile.am
index 4ddd12d..514900a 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -23,6 +23,8 @@ EXTRA_DIST = LICENSE ChangeLog.v1 ChangeLog.libgcj                    \
        libffi.xcodeproj/project.pbxproj                                \
        libtool-ldflags
 
+# local.exp is generated by configure
+CLEANFILES = local.exp
 
 ## ################################################################