[RFA v3 11/13] Improve "backtrace" help text

[Tom Tromey <tom@tromey.com>]

This improves help text in stack.c in two ways.  First, it removes
trailing newlines from various help strings.  I think these are never
needed.  Second, it adds a "Usage" line to the "backtrace" text, as
suggested by Pedro.

gdb/ChangeLog
2018-03-23  Tom Tromey  <tom@tromey.com>

	* stack.c (_initialize_stack): Remove trailing newlines from help
	text.  Add "Usage" line to "backtrace" help.
---
 gdb/ChangeLog |  5 +++++
 gdb/stack.c   | 13 +++++++------
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/gdb/stack.c b/gdb/stack.c
index 16f7931be1..427b182c7f 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -2554,22 +2554,23 @@ This is useful in command scripts."));
 Select and print a stack frame.\nWith no argument, \
 print the selected stack frame.  (See also \"info frame\").\n\
 An argument specifies the frame to select.\n\
-It can be a stack frame number or the address of the frame.\n"));
+It can be a stack frame number or the address of the frame."));
 
   add_com_alias ("f", "frame", class_stack, 1);
 
   add_com_suppress_notification ("select-frame", class_stack, select_frame_command, _("\
 Select a stack frame without printing anything.\n\
 An argument specifies the frame to select.\n\
-It can be a stack frame number or the address of the frame.\n"),
+It can be a stack frame number or the address of the frame."),
 		 &cli_suppress_notification.user_selected_context);
 
   add_com ("backtrace", class_stack, backtrace_command, _("\
 Print backtrace of all stack frames, or innermost COUNT frames.\n\
-With a negative argument, print outermost -COUNT frames.\nUse of the \
-'full' qualifier also prints the values of the local variables.\n\
+Usage: backtrace [QUALIFIERS]... [COUNT]\n\
+With a negative argument, print outermost -COUNT frames.\n\
+Use of the 'full' qualifier also prints the values of the local variables.\n\
 Use of the 'no-filters' qualifier prohibits frame filters from executing\n\
-on this backtrace.\n"));
+on this backtrace."));
   add_com_alias ("bt", "backtrace", class_stack, 0);
 
   add_com_alias ("where", "backtrace", class_alias, 0);
@@ -2587,7 +2588,7 @@ on this backtrace.\n"));
   if (dbx_commands)
     add_com ("func", class_stack, func_command, _("\
 Select the stack frame that contains <func>.\n\
-Usage: func <name>\n"));
+Usage: func <name>"));
 
   add_setshow_enum_cmd ("frame-arguments", class_stack,
 			print_frame_arguments_choices, &print_frame_arguments,
-- 
2.13.6