RFR (XS) : 8139707 : [TESTBUG] Quarantine unstable compiler/jvmci tests

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev/8139707/webrev.00/
> 3 lines changed: 3 ins; 0 del; 0 mod; 

Hi all,

please review the patch which adds @ignore to three compiler/jvmci tests:
 - compiler/jvmci/compilerToVM/MaterializeVirtualObjectTest.java fails w/ Xcomp due to JDK-8139703 
 - compiler/jvmci/compilerToVM/DisassembleCodeBlobTest.java and InvalidateInstalledCodeTest.java intermittently fail in some configuration due to JDK-8139700

bug : https://bugs.openjdk.java.net/browse/JDK-8139707

Thanks,
- Igor