RFR: 8144712: Remove g1RootClosures.inline.hpp

[Erik Helin]

Hi all,

this small patches removes the no longer needed file
g1RootClosures.inline.hpp. The class G1EvacuationClosures can live in
g1RootClosures.hpp and G1SharedClosures gets its own file.

Enhancement:
https://bugs.openjdk.java.net/browse/JDK-8144712

Webrev:
http://cr.openjdk.java.net/~ehelin/8144712/webrev.00/

Testing:
- JPRT
- GC test suite with full verification

Thanks,
Erik