libgmp: fix for multilib header installation

libgmp/.footprint

@@ -1,5 +1,6 @@
 drwxr-xr-x	root/root	usr/
 drwxr-xr-x	root/root	usr/include/
+-rw-r--r--	root/root	usr/include/gmp-64.h
 -rw-r--r--	root/root	usr/include/gmp.h
 -rw-r--r--	root/root	usr/include/gmpxx.h
 drwxr-xr-x	root/root	usr/lib/

libgmp/.md5sum

@@ -1 +1,2 @@
 06fe2ca164221c59ce74867155cfc1ac  gmp-5.1.2.tar.xz
+bbf6d30f092c6d302f028679f1f9bfc3  gmp.h

libgmp/Pkgfile

@@ -4,8 +4,9 @@
 
 name=libgmp
 version=5.1.2
-release=1
-source=(ftp://ftp.gmplib.org/pub/gmp-$version/gmp-$version.tar.xz)
+release=2
+source=(ftp://ftp.gmplib.org/pub/gmp-$version/gmp-$version.tar.xz \
+    gmp.h)
 
 build() {
     cd gmp-$version
@@ -14,5 +15,7 @@ build() {
                 --build=x86_64-unknown-linux-gnu
     make
     make DESTDIR=$PKG install
+    mv $PKG/usr/include/gmp{,-64}.h
+    cp $SRC/gmp.h $PKG/usr/include/
     rm -r $PKG/usr/share
 }

libgmp/gmp.h

@@ -0,0 +1,16 @@
+/* gmp.h stub */
+
+#ifndef __STUB__GMP_H__
+#define __STUB__GMP_H__
+
+#if defined(__x86_64__) || \
+    defined(__sparc64__) || \
+    defined(__arch64__) || \
+    defined(__powerpc64__) || \
+    defined(__s390x__)
+#include "gmp-64.h"
+#else
+#include "gmp-32.h"
+#endif
+
+#endif