Straightforward fatal to internal_error conversions

This commit replaces most of the calls to fatal that represent
internal errors with calls to internal_error, either directly
or via gdb_assert and gdb_assert_not_reached.

gdb/gdbserver/
2014-08-06  Gary Benson  <gbenson@redhat.com>

	* inferiors.c (get_thread_process): Replace check with gdb_assert.
	* linux-low.c (linux_wait_for_event_filtered): Replace fatal with
	internal_error.
	(linux_resume_one_lwp): Likewise.
	* linux-x86-low.c (x86_siginfo_fixup): Replace checks with
	gdb_assert.
	* mem-break.c (raw_bkpt_type_to_target_hw_bp_type): Replace fatal
	with internal_error.
	* regcache.c (get_thread_regcache): Replace check with gdb_assert.
	(init_register_cache): Replace fatal with gdb_assert_not_reached.
	(find_register_by_name): Replace fatal with internal_error.
	(find_regno): Likewise.
	* tdesc.c (init_target_desc): Replace check with gdb_assert.
	* thread-db.c (thread_db_create_event): Likewise.
	(thread_db_load_search): Likewise.
	(try_thread_db_load_1): Likewise.
	* tracepoint.c (get_jump_space_head): Replace fatal with
	internal_error.
	(claim_trampoline_space): Likewise.
	(have_fast_tracepoint_trampoline_buffer): Likewise.
	(cmd_qtstart): Likewise.
	(stop_tracing): Likewise.
	(fast_tracepoint_collecting): Likewise.
	(target_malloc): Likewise.
	(download_tracepoint): Likewise.
	(download_trace_state_variables): Replace check with gdb_assert.
	(upload_fast_traceframes): Replace fatal with internal_error.
Convert fatal to gdb_assert in both i386_dr_low_set_addr

This commit converts if..fatal checks in both i386_dr_low_set_addr
implementations to gdb_asserts.  It's not obvious from the context,
but the conditional in both cases is changed to match the equivalent
conditional in the i386_dr_low_get_addr implementations.  Nothing
fundamental has changed because DR_FIRSTADDR is zero.  This commit
also removes a vague comment in Linux i386_dr_low_get_addr.  I could
have reworded the comment (and replicated it three times for the other
identical assertions) but I think the existence of specific functions
for the status and control registers makes it fairly obvious what is
going on.

gdb/gdbserver/
2014-08-06  Gary Benson  <gbenson@redhat.com>

	* linux-x86-low.c (i386_dr_low_set_addr): Replace check with
	gdb_assert.
	(i386_dr_low_get_addr): Remove vague comment.
	(win32-i386-low.c): Replace check with gdb_assert.
Downgrade fatal to warning in linux_async

This commit downgrades a fatal error to a warning in linux_async.
linux_async is called from two different places in gdbserver:

 Via target_async from handle_accept_event.  The argument
   is always zero, so The warning will never be printed here

 Via start_non_stop from handle_general_set.  This prints
   its own error message to stderr on failure, which will
   be preceded by the warning if it is emitted.

gdb/gdbserver/
2014-08-06  Gary Benson  <gbenson@redhat.com>

	* linux-low.c (linux_async): Replace fatal with warning.
	Tidy up and return.
	(linux_start_non_stop): Return -1 if linux_async failed.
Convert fatal to error in remote_prepare

This commit converts a call to fatal in remote_prepare with a call to
error.  remote_prepare is called precisely once, from main, at a point
where jumping to toplevel will call exit (1), so error and fatal are
functionally equivalent at this point.  Note that remote_prepare calls
perror_with_name (which calls error) so callers of remote_prepare must
already handle the fact that it may exit via longjmp.

gdb/gdbserver/
2014-08-06  Gary Benson  <gbenson@redhat.com>

	* remote-utils.c (remote_prepare): Replace fatal with error.
Convert fatal to perror_with_name in IPA code

This commit converts four calls to fatal into calls to
perror_with_name.  perror_with_name calls error, which
in IPA terminates with exit (1) rather than longjmp, so
there is no functional change here.

gdb/gdbserver/
2014-08-06  Gary Benson  <gbenson@redhat.com>

	* tracepoint.c (gdb_agent_init): Replace fatal with
	perror_with_name.
	(initialize_tracepoint): Likewise.
Remove fatalfunction and prototype

This commit removes the now-unused fatal function and prototype.

gdb/gdbserver/
2014-08-06  Gary Benson  <gbenson@redhat.com>

	* utils.h (fatal): Remove declaration.
	* utils.c (fatal): Remove function.