6837982: SCTP API docs not being generated

Update docs makefile to build javadoc for the com.sun.nio.sctp package.

Reviewed-by: jccollet, alanb, weijun

jdk/make/docs/Makefile

@@ -323,6 +323,30 @@ HTTPSERVER_DOCTITLE    = "Java$(TRADEMARK) HTTP Server"
 HTTPSERVER_JAVADOCHEADER      = "Java HTTP Server"
 # HTTPSERVER_PKGS is located in NON_CORE_PKGS.gmk
 
+#
+# Variables used by sctp target
+#
+
+SCTPAPI_SOURCEPATH  = $(TOPDIR)/src/share/classes
+SCTPAPI_DOCDIR   = $(DOCSDIR)/jre/api/nio/sctp/spec
+
+SCTPAPI_JAVADOCFLAGS = $(COMMON_JAVADOCFLAGS)                           \
+                   -encoding ascii                                      \
+                   -nodeprecatedlist                                    \
+                   -d $(SCTPAPI_DOCDIR)                                 \
+                   -sourcepath $(SCTPAPI_SOURCEPATH)                    \
+                   -windowtitle $(SCTPAPI_WINDOWTITLE)                  \
+                   -doctitle $(SCTPAPI_DOCTITLE)                        \
+                   -header $(SCTPAPI_JAVADOCHEADER)                     \
+                   -bottom $(SCTPAPI_JAVADOCBOTTOM)			\
+                   -linkoffline ../../../../../api $(DOCSDIR)/api/
+
+SCTPAPI_WINDOWTITLE = "SCTP API"
+SCTPAPI_DOCTITLE    = "SCTP API"
+SCTPAPI_JAVADOCHEADER      = "SCTP API"
+SCTPAPI_JAVADOCBOTTOM = '<font size="-1"><a href="http://bugs.sun.com/services/bugreport/index.jsp">Report a bug or request a feature.</a><br>Copyright $(THIS_YEAR) Sun Microsystems, Inc. All Rights Reserved. Use is subject to license terms.</font>'
+# SCTPAPI_PKGS is located in NON_CORE_PKGS.gmk
+
 #
 # Variables used by jvmti target
 #
@@ -451,6 +475,7 @@ ALL_OTHER_TARGETS = \
     smartcardiodocs \
     tracingdocs \
     httpserverdocs  \
+    sctpdocs \
     mgmtdocs \
     attachdocs \
     jconsoledocs \
@@ -631,6 +656,14 @@ httpserverdocs:
 	$(JAVADOC_CMD) $(HTTPSERVER_JAVADOCFLAGS)                     \
 		   $(HTTPSERVER_PKGS)
 
+.PHONY: sctpdocs
+sctpdocs:
+	@# ######## api-sctp #######################
+	$(RM) -r $(SCTPAPI_DOCDIR)
+	$(MKDIR) -p $(SCTPAPI_DOCDIR)
+	$(JAVADOC_CMD) $(SCTPAPI_JAVADOCFLAGS)                     \
+		$(SCTPAPI_PKGS)
+
 .PHONY: mgmtdocs
 mgmtdocs: $(COPY-MIB-TARGET)
 	@# ######## api-management ############################