hg: jdk9/dev: 8171929: "make docs" in clean forest is broken

[erik.joelsson at oracle.com]

Changeset: 7b09422f5c83
Author:    erikj
Date:      2017-01-04 16:58 +0100
URL:       http://hg.openjdk.java.net/jdk9/dev/rev/7b09422f5c83

8171929: "make docs" in clean forest is broken
Reviewed-by: mchung, tbell

! make/Main.gmk