[RFC] usage of environment variable from the command line

[Eli Zaretskii]

> Cc: denis.pilat@st.com,  gdb-patches@sourceware.org
> From: Jim Blandy <jimb@codesourcery.com>
> Date: Tue, 25 Sep 2007 10:11:44 -0700
> 
> 
> When I said, "For the other cases", I meant the cases other than
> source-language expressions

Sorry for my misunderstanding.