RFR: 8168915: [JVMCI] use MethodParameters attribute instead of depending on -g option for sanity checks

[Doug Simon]

> On 29 Oct 2016, at 03:31, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> Thank you Doug,
> 
> Looks good to me (not expert). I will test it with AOT.
> 
> I see only 3% size increase vs 10% with -g.

I wonder if 3% is still too large for the JDK? If not, it would be great to see JDK jars/modules built with this on by default.

> I can replace '-g' with '-parameters' javac option for AOT modules when the fix is integrated.

Great. Thanks for the review.

-Doug

> On 10/28/16 4:22 PM, Doug Simon wrote:
>> In light of discussion[1] about build changes for 8166416 with respect to -g, this patch enables JVMCI to expose parameter info available in the MethodParameters class file attribute[2] (produced by the -parameters javac option) instead of relying on the LocalVariableTable attribute (produced by -g).
>> 
>> I’m assuming the class file expansion caused by -parameters is significantly less than -g although I’m surprised to see that parameter info is missing from the JDK classes as noted in the JBS issue.
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8168915
>> http://cr.openjdk.java.net/~dnsimon/8168915/
>> 
>> -Doug
>> 
>> [1] http://mail.openjdk.java.net/pipermail/hotspot-dev/2016-October/025051.html
>> [2] https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.24
>>