RFR: SA: JDK-8189798: SA cleanup - part 1

[Jini George]

Hello,

As a part of SA next, I am working on writing a test case which compares 
the fields and the types of the fields of the SA java classes with the 
corresponding entries in the vmStructs tables. This, to some extent, 
would help in preventing errors in SA due to the changes in hotspot. As 
a precursor to this, I am in the process of making some cleanup related 
changes (mostly in SA). I plan to have the changes done in parts. For 
this webrev, most of the changes are for:

1. Avoiding having some values being redefined in SA. Instead have those 
exported through vmStructs, and read it in SA. 
(CompactibleFreeListSpace::_min_chunk_size_in_bytes, 
CompactibleFreeListSpace::IndexSetSize)

Redefinition of hotspot values in SA makes SA error prone, when the 
value gets altered in hotspot and the corresponding modification gets 
missed out in SA.

2. To remove some unused code (JNIid.java).
3. Add the missing "CMSBitMap::_bmStartWord" in vmStructs.
4. Modify variable names in SA and hotspot to match the counterpart 
names, so that the comparison of the fields become easier. Most of the 
changes belong to this group.

Could I please get reviews done for these precursor changes ?

JBS Id: https://bugs.openjdk.java.net/browse/JDK-8189798
webrev: http://cr.openjdk.java.net/~jgeorge/8189798/webrev.00/

Thank you,
Jini.