RFR: 8233885: Test fails with assert(comp != __null) failed: Ensure we have a compiler

[Jie Fu]

Hi all,

May I get reviews for this small change?
This bug was found by running 
compiler/profiling/spectrapredefineclass/Launcher.java with -Xcomp.
The fix sets CompLevel_initial_compile to CompLevel_full_optimization if 
CompilationMode=high-only is specified.

JBS:    https://bugs.openjdk.java.net/browse/JDK-8233885
Webrev: http://cr.openjdk.java.net/~jiefu/8233885/webrev.00/

Testing:
   - make test TEST="test/hotspot/jtreg/compiler" CONF=fastdebug on 
Linux/x64

Thanks a lot.
Best regards,
Jie