hg: jdk/sandbox: 8196988: Resolve disabled warnings for libjimage

[chris.hegarty at oracle.com]

Changeset: 929621cf06b4
Author:    sdama
Date:      2018-06-18 08:07 +0530
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/929621cf06b4

8196988: Resolve disabled warnings for libjimage
Summary: Fixed warnings related to implicit-fallthrough gcc option
Reviewed-by: psandoz, mchung

! make/lib/CoreLibraries.gmk
! src/java.base/share/native/libjimage/imageDecompressor.cpp