Size field in OBJECT_ALLOC event should be in number of bytes as
documented in JVMPI spec.

struct {
  jint arena_id;
  jobjectID class_id;
  jint is_array;
  jint size;
  jobjectID obj_id;
} obj_alloc;

Contents:

  arena_id - arena where allocated.
  class_id - class to which this object belongs, or the array element class if is_array is JVMPI_CLASS.
  is_array - values can be:
              JVMPI_NORMAL_OBJECT normal object
              JVMPI_CLASS array of objects
              JVMPI_BOOLEAN array of booleans
              JVMPI_BYTE array of chars
              JVMPI_CHAR array of chars
              JVMPI_SHORT array of shorts
              JVMPI_INT array of ints
              JVMPI_LONG array of longs
              JVMPI_FLOAT array of floats
              JVMPI_DOUBLE array of doubles
  size - size in number of bytes.
  obj_id - unique object ID.

There is a bug in hotspot that just passes the internal "size", which is
number of words, to jvmpi::post_object_alloc_event.