[9] RFR(S/M): 8166377: is_compiled_by_jvmci hot in some profiles - improve nmethod compiler type detection

[Nils Eliasson]

Hi,

Please review this change. It touches many files but is not complex.

Description:
We have seen a performance regression in some benchmarks where 
nmethod::is_compiled_by_jvmci() has been hot. That method is used is a 
workaround in CompiledMethod::is_deopt_entry(). The workaround remains 
for the moment, this fix makes it less costly.

Summary:
This fix removes the compiler reference from the codeblobs and instead 
performs the compiler type check on a constant, this removes a double 
dereference when checking the compiler. I also took the time to properly 
add the compiler types to the constructors.


bugs: https://bugs.openjdk.java.net/browse/JDK-8166377
webrev: http://cr.openjdk.java.net/~neliasso/8166377/

Regards,
Nils Eliasson