Add parallel recompilation time to histogram and plot execution pause times.

src/vm-state-inl.h

Index: src/vm-state-inl.h
diff --git a/src/vm-state-inl.h b/src/vm-state-inl.h
index 384940dfa56ec78f20d4c8baceb6be66e29572b4..97febd028340c6bf05786c70e8b8f7ed7fe3d2ed 100644
--- a/src/vm-state-inl.h
+++ b/src/vm-state-inl.h
@@ -47,8 +47,8 @@ inline const char* StateToString(StateTag state) {
       return "GC";
     case COMPILER:
       return "COMPILER";
-    case PARALLEL_COMPILER_PROLOGUE:
-      return "PARALLEL_COMPILER_PROLOGUE";
+    case PARALLEL_COMPILER:
+      return "PARALLEL_COMPILER";
     case OTHER:
       return "OTHER";
     case EXTERNAL: