-fno-leading-underscore on darwin

[Mike Stump <mrs at apple dot com>]

Here is a small patch that improves the functionality for 
-fno-leading-underscore on powerpc-apple-darwin7.4.0 that I checked in 
as obvious.  Here are the regressions I put in:

====== g++.sum ===========
====== gcc.sum ===========
Tests that now fail, but worked before:

gcc.c-torture/compile/20001226-1.c  -O3 -g  (test for excess errors)
gcc.dg/tree-ssa/20040615-1.c scan-tree-dump-times bar2 0

Tests that now work, but didn't before:

gcc.dg/tree-ssa/20040615-1.c scan-tree-dump-times bar2 0

====== libffi.sum ===========
====== libjava.sum ===========
====== libmudflap.sum ===========
====== libstdc++.sum ===========
====== objc.sum ===========

And the patch:

Attachment: no-under.diffs.txt
Description: Text document

All the regressions are spurious.