Review request (XS): 8023227: Enhance layout_helper_log2_element_size assert

[Stefan Karlsson]

http://cr.openjdk.java.net/~stefank/8023227/webrev.00

Print the values of l2esz and lh when we hit the assert:
assert(l2esz <= LogBitsPerLong, "sanity");

thanks,
StefanK