RFR: 8240751: Shenandoah: fold ShenandoahTracer definition [v2]

[Aleksey Shipilev]

> Currently, we have `shenandoahTracer.hpp` with a sole definition:
> class ShenandoahTracer : public GCTracer {
> public:
>   ShenandoahTracer() : GCTracer(Shenandoah) {}
> };
> 
> This can be folded near the only use at `shenandoahCollectorPolicy.hpp`.

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Leftover include of deleted file

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/55/files
  - new: https://git.openjdk.java.net/jdk/pull/55/files/f2a8df43..51b7572f

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=55&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=55&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/55.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/55/head:pull/55

PR: https://git.openjdk.java.net/jdk/pull/55