RFR: Verifier should use BP::get_raw when getting _loc fwdptr

[Aleksey Shipilev]

This is similar to what we have elsewhere:

$ hg diff
diff -r fe8f1450f82b src/share/vm/gc/shenandoah/shenandoahVerifier.cpp
--- a/src/share/vm/gc/shenandoah/shenandoahVerifier.cpp	Mon Sep 11 14:59:19 2017 +0200
+++ b/src/share/vm/gc/shenandoah/shenandoahVerifier.cpp	Mon Sep 11 15:04:39 2017 +0200
@@ -147,7 +147,7 @@
       msg.append("Matrix connections:\n");

       oop fwd_to = (oop) BrooksPointer::get_raw(obj);
-      oop fwd_from = BrooksPointer::forwardee(_loc);
+      oop fwd_from = (oop) BrooksPointer::get_raw(_loc);

       size_t from_idx = _heap->heap_region_index_containing(_loc);
       size_t to_idx = _heap->heap_region_index_containing(obj);

Testing: hotspot_gc_shenandoah

Thanks,
-Aleksey