RFR (round2) JDK-8038654: Separate SymbolTable and StringTable code

[Gerard Ziemski]

hi all,

Please review this simple enhancement, which refactors symbolTable into symbolTable and stringTable

The changes since rev0:

Re: Stefan Karlsson

- sorted includes
- replaced "#include symbolTable.hpp" with just "#include stringTable.hpp" as needed
- stringTable.cpp no longer includes symbolTable.hpp
- stringTable.hpp forward declares Symbol instead of including symbolTable.hpp


Webrev: http://cr.openjdk.java.net/~gziemski/8038654_rev1
Bug: https://bugs.openjdk.java.net/browse/JDK-8038654

Tested with hotspot jtreg, vm.quicklooks and JPRT. Locally builds on Mac OS X and Linux.

Thank you.