Added support for showing which constant is used.
Added support for showing which constant is used.

From PHP bug 61602: https://bugs.php.net/bug.php?id=61602

hnw/vld,i17c/vld,sigma-random/vld,i17c/vld,sigma-random/vld,sigma-random/vld,derickr/vld,derickr/vld,hnw/vld,derickr/vld,hnw/vld,derickr/vld,i17c/vld,hnw/vld,i17c/vld