RFR(S): 8145331: SEGV in DirectivesStack::release(DirectiveSet*)

[Nils Eliasson]

Hi,

Please review this patch:

Description:
In the fix for JDK-8144873 I updated only one of the two use cases of 
CompilerDirectives::get_for(AbstractCompiler..)

Summary:
I simplify CompilerDirectives::get_for(..) to always return the c1_store 
for all unsupported cases. Makes getMatchingDirective and 
getDefaultDirective simpler too. Moved refcount out of get_for(...) 
since it is not guaranteed to be used if updated here.

Testing:
All intrinsic tests and all compilercontrol tests in addition to testset 
hotspot.
IntrinsicAvailableTest is updated to not check JVMCI compiler for 
intrinsics.
IntrinsicDisabledTest.jtr doesn't work with JVMCI - no action taken
NullCheckDroppingsTest.jtr doesn't work - since JVMCI doesn't support 
BackgroudCompilation - no action taken

Bug: https://bugs.openjdk.java.net/browse/JDK-8145331
Webrev: http://cr.openjdk.java.net/~neliasso/8145331/webrev.01/

Regards,
Nils Eliasson