hg: jdk/jdk: 8196993: Resolve disabled warnings for libunpack

[srinivas.dama at oracle.com]

Changeset: 2a524e603529
Author:    sdama
Date:      2018-06-12 14:16 +0530
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/2a524e603529

8196993: Resolve disabled warnings for libunpack
Summary: captured return values and labelled as fall through to avoid unused-result and implicit-fallthrough gcc warnings
Reviewed-by: mchung

! make/launcher/Launcher-jdk.pack.gmk
! src/jdk.pack/share/native/common-unpack/unpack.cpp
! src/jdk.pack/share/native/common-unpack/zip.cpp