Subject: RFR(XS): 8204701: [TESTBUG] runtime/SharedArchiveFile/BootAppendTests.java should handle mapping failure

[mikhailo]

     JBS: https://bugs.openjdk.java.net/browse/JDK-8204701
     Webrev: http://cr.openjdk.java.net/~mseledtsov/8204701.00/
     Testing:
         1. Locally: ran the affected test - PASS
         2. Distributed test system: hs-tier1 and hotspot_cds

Thank you,
Misha