Make writing to files work properly. (Fixes to BFD are also needed.)

* core.c (core_open):  Open file ourselves, read or r/w, depending on
write_files.  Use bfd_fdopenr.
* gdbcore.h (write_files):  New variable.
* exec.c (write_files):  Define variable, add set&show for it.
(exec_file_command):  Use write_files to open for read or r/write.

Make shared library reading happen automatically.  These changes
are mostly from Peter Schauer <pes@regent.e-technik.tu-muenchen.de>.

* inferior.h (stop_soon_quietly):  Add to exported variables.
* infrun.c (child_create_inferior):  call solib hook, if defined.
(child_attach):  call solib hook, if defined.
* solib.c:  Include inferior.h.  Add from_tty to so_list as kludge.
(find_solib):  Use lookup_misc_func rather than hand-rolled.
(symbol_add_stub):  New stub for catch_errors.
(solib_add):  Avoid output if !from_tty.  Catch errors rather
than just calling symbol_file_add and bombing.
(solib_create_inferior_hook):  Interface with the target process
to let it read and alloc shared libs, then figure out what it did.

* core.c (validate_files):  Fix typo, soften warning.
(Fix from Hiroto Kagotani <kagotani@cs.titech.ac.jp>.)

* utils.c (fputs_demangled):  Avoid duplicate printing if
demangling is off.  (Fix from J.T. Conklin <jtc@cayenne.com>.)

* infrun.c (proceed):  Cast -1 to (CORE_ADDR) before comparing.
(Fix from pierre@la.tce.com (Pierre Willard).)

* main.c (catch_errors):  Change argument to a char * from an int,
since a char * can point to a struct full of glop, but an int
is not guaranteed to be able to hold a pointer.
* breakpoint.c (breakpoint_cond_eval, bpstat_stop_status,
breakpoint_re_set_one, breakpoint_re_set):  Adapt.
* core.c (core_open, solib_add_stub):  Adapt.
* remote-vx.c (symbol_stub, add_symbol_stub, callers):  Adapt.

gdb/inferior.h

@@ -4,19 +4,19 @@
 
 This file is part of GDB.
 
-GDB is free software; you can redistribute it and/or modify
+This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 1, or (at your option)
-any later version.
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
 
-GDB is distributed in the hope that it will be useful,
+This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
-along with GDB; see the file COPYING.  If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 /* For bpstat.  */
 #include "breakpoint.h"
@@ -87,6 +87,13 @@ extern void init_wait_for_inferior ();
 extern void close_exec_file ();
 extern void reopen_exec_file ();
 
+/* From infcmd.c */
+void attach_command (
+#ifdef __STDC__
+		     char *arg, int from_tty
+#endif
+		     );
+		     
 /* Last signal that the inferior received (why it stopped).  */
 
 extern int stop_signal;
@@ -145,6 +152,13 @@ extern int step_over_calls;
 
 extern int step_multi;
 
+/* Nonzero means expecting a trap and caller will handle it themselves.
+   It is used after attach, due to attaching to a process;
+   when running in the shell before the child program has been exec'd;
+   and when running some kinds of remote stuff (FIXME?).  */
+
+int stop_soon_quietly;
+
 /* Nonzero if proceed is being used for a "finish" command or a similar
    situation when stop_registers should be saved.  */