RFR(S) 8007270: Make IsMethodCompilable test work with tiered

[Nils Eliasson]

Hi all,

I need a review for this change.

http://cr.openjdk.java.net/~neliasso/8007270/webrev.01/

This test was disabled since it didn't work very well with tiered (or 
client). It tests the PerMethodRecompilationCutoff that was introduced 
to disable c2-compilations of a method when it has been deoptimized too 
many times.  The bug report suggested we should disable c1 compilations 
as well but I don't think that was the intent of the cutoff feature.

I have changed the following in the test
* skip test when running client only (not supported by jtreg at the moment)
* check what compilation level was used when compiling so that it can 
keep track of the number of c2 compiles (and deopts) correctly in tiered 
mode
* compile and deopt up to the cutoff limit only once
* added PerMethodRecompilationCutoff=4 flag to commandline to reduce 
wasted time in test (default 400)

Now the test works and the running time has been reduced to seconds 
instead of minutes.

Kind regards,
Nils Eliasson