To do that a small enhancement to vg_regtest was needed:
(1) New declaration to allow specifying an environemnt variable
that is set prior to invoking valgrind.
eg: env: VAR=VAL
There can be more than one such declaration
(2) prog-asis: program_name
This is like prog: except the program name is not prefixed with
the testdir.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15064