change existence test to allow mail folders > 2GB, sr=mscott 361730

xpcom/obsolete/nsFileSpecUnix.cpp

@@ -158,8 +158,7 @@ char* nsFileSpec::GetLeafName() const
 PRBool nsFileSpec::Exists() const
 //----------------------------------------------------------------------------------------
 {
-    struct stat st;
-    return !mPath.IsEmpty() && 0 == stat(mPath, &st); 
+    return !mPath.IsEmpty() && 0 == access(mPath, F_OK); 
 } // nsFileSpec::Exists
 
 //----------------------------------------------------------------------------------------