patch 8.2.0320: no Haiku support

Problem:    No Haiku support.
Solution:   Add support for Haiku. (Emir Sari, closes #5605)
diff --git a/runtime/doc/Makefile b/runtime/doc/Makefile
index 65dc843..b1b4c8e 100644
--- a/runtime/doc/Makefile
+++ b/runtime/doc/Makefile
@@ -64,6 +64,7 @@
 	os_amiga.txt \
 	os_beos.txt \
 	os_dos.txt \
+	os_haiku.txt \
 	os_mac.txt \
 	os_mint.txt \
 	os_msdos.txt \
@@ -204,6 +205,7 @@
 	os_amiga.html \
 	os_beos.html \
 	os_dos.html \
+	os_haiku.html \
 	os_mac.html \
 	os_mint.html \
 	os_msdos.html \
@@ -422,6 +424,9 @@
 os_dos.txt:
 	touch os_dos.txt
 
+os_haiku.txt:
+	touch os_haiku.txt
+
 os_mac.txt:
 	touch os_mac.txt