bug#41585: Default value of "libdir" is incorrect

[Jacob Bachmeyer]

I have finally replicated an issue (where stats.exp mysteriously failed 
on his machine but passes on mine) Rob Savoye had mentioned in private 
emails a few times and it has an impressively bizarre actual trigger:  
the inner runtest(1) invocations from testsuite/runtest.main/stats.exp 
fail to start unless the DejaGnu sources were checked out into a 
directory literally named 'dejagnu' (all lowercase, without the 
quotes).  The inner runtest(1) invocations for the options.exp tests are 
not affected because they do not actually run any tests and options.exp 
matches the output it checks before runtest(1) prepares to run tests.

The problem is that the inner testsuite used for stats.exp is very 
minimal and this causes DejaGnu to search "libdir" (which is set 
incorrectly in runtest.exp) for a default configuration in 
runtest.exp:load_tool_target_config.  The runtest.exp file is located in 
the correct libdir, whether in a source checkout or installed, but the 
code in runtest.exp currently expects runtext.exp to be 
LPREFIX/SOMETHING/runtest.exp and sets libdir to LPREFIX/dejagnu.  If 
the sources are checked out in a 'dejagnu' directory, this happens to 
work.  If DejaGnu is installed, this happens to work (runtest.exp is 
placed in PREFIX/share/dejagnu by default).  If the sources are in any 
other directory, this does not work.

Report filed to get a bug number to go with the fix.  Thanks to Rob 
Savoye for mentioning the test failures.

-- Jacob