Add `configure.host` to the `EXTRA_DIST` files
When running `make dist`, `configure.host` would not result in the distribution tarball, however `configure` would try to read it, and as such the tarball would not be buildable.
diff --git a/Makefile.am b/Makefile.am
index 4ddd12d..9b6b34c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -21,7 +21,7 @@
m4/ltversion.m4 src/debug.c msvcc.sh \
generate-darwin-source-and-headers.py \
libffi.xcodeproj/project.pbxproj \
- libtool-ldflags
+ libtool-ldflags configure.host
## ################################################################
