Hello,

This patch extends the inside_main_func() check so that, when "main" 
isn't found in the symbol table,  the mimimal symbol table is searched. 
  In case you're wondering, the logic for finding the end address of 
"main" was cobbled together from random bits of code from blockframe and 
the alpha.  It certainly appears to work for d10v and i386.

Anyway, with this, the d10v's assembler backtrace stops at main goving 
the short 'n' sharp backtrace

	foo2
	main

instead of the current:

	foo2
	main
	_start
	_start

The patch (since things now stop in "main") also removes the d10v 
specific frame ID eq test; and updates the testsuite so that it doesn't 
allow "_start" in the backtrace.

I intend checking this into both 6.0 branch and mainline in a few days.

comments,
Andrew