multilib_header.bbclass: Add oe_multilib_header wrapper

This helper function and associated header will allow us to
resolve two/three header files that conflict due to contents
that change based on wordsize and ABI.

(From OE-Core rev: 1fe66d01b7bce70a37245d47b1abce155fae926e)

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/multilib_header.bbclass

@@ -0,0 +1,29 @@
+inherit siteinfo
+
+# If applicable on the architecture, this routine will rename the header and add
+# a unique identifier to the name for the ABI/bitsize that is being used.  A wrapper will
+# be generated for the architecture that knows how to call all of the ABI variants for that
+# given architecture.
+#
+# TODO: mips64 n32 is not yet recognized in this code
+# when that is identified the name of the wrapped item should be "n32" and appropriately
+# determined int he if coding...
+#
+oe_multilib_header() {
+	# Do nothing on ARM, only one ABI is supported at once
+	if echo ${TARGET_ARCH} | grep -q arm; then
+	    return
+	fi
+	for each_header in "$@" ; do
+	   if [ ! -f "${D}/${includedir}/$each_header" ]; then
+	      bberror "oe_multilib_header: Unable to find header $each_header."
+	      continue
+	   fi
+	   stem=$(echo $each_header | sed 's#\.h$##')
+	   ident=${SITEINFO_BITS}
+	   # if mips64/n32 set ident to n32
+	   mv ${D}/${includedir}/$each_header ${D}/${includedir}/${stem}-${ident}.h
+
+	   sed -e "s#ENTER_HEADER_FILENAME_HERE#${stem}#g" ${COREBASE}/scripts/multilib_header_wrapper.h > ${D}/${includedir}/$each_header
+	done
+}