Request for review: 7168280: Eliminate the generic signature index slot from field array for field without generic signature

[Jiangli Zhou]

Hi,

The field array is an array of 7-shorts [access, name index, sig index, 
initval index, low offset, high offset, generic signature index]. Most 
fields don't have generic signature attribute, in that case the generic 
signature index in the field array is 0 and unused. For all classes in 
rt.jar, there are total about 28973 fields. From which 27466 fields do 
not have generic signature and only 1507 fields have generic signature.

Following is a webrev that eliminates the unused generic signature index 
slot from field array. For field without generic signature, the field 
data is 6-shorts. For field with generic signature, it is still 7-shorts 
of data. A new flag is added in the field access flag to indicate if the 
field has the extra short for generic signature index.

   http://cr.openjdk.java.net/~jiangli/7168280/webrev.00/

Thanks,

Jiangli