Use SaL symbol name when reporting breakpoint locations

Currently, "info break" can show some (perhaps) unexpected results when
setting a breakpoint on an inlined function:

(gdb) list
1	#include <stdio.h>
2
3	static inline void foo()
4	{
5	        printf("Hello world\n");
6	}
7
8	int main()
9	{
10	        foo();
11	        return 0;
12	}
13
(gdb) b foo
Breakpoint 1 at 0x400434: file foo.c, line 5.
(gdb) i b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x0000000000400434 in main at foo.c:5

GDB reported that we understood what "foo" was, but we then report that the
breakpoint is actually set in main. While that is literally true, we can
do a little better.

This is accomplished by copying the symbol for which the breakpoint was set
into the bp_location.  From there, print_breakpoint_location can use this
information to print out symbol information (if available) instead of calling
find_pc_sect_function.

With the patch installed,

(gdb) i b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x0000000000400434 in foo at foo.c:5

gdb/ChangeLog:

	* breakpoint.c (print_breakpoint_location): Use the symbol saved
	in the bp_location, falling back to find_pc_sect_function when
	needed.
	(add_location_to_breakpoint): Save sal->symbol.
	* breakpoint.h (struct bp_location) <symbol>: New field.
	* symtab.c (find_function_start_sal): Save the symbol into the SaL.
	* symtab.h (struct symtab_and_line) <symbol>: New field.

gdb/testsuite/ChangeLog:

	* gdb.opt/inline-break.exp (break_info_1): New procedure.
	Test "info break" for every inlined function breakpoint.

1 files changed, 6 insertions, 2 deletions

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index ada72e0..10fccb8 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -5956,8 +5956,11 @@ print_breakpoint_location (struct breakpoint *b,
     uiout->field_string ("what", event_location_to_string (b->location.get ()));
   else if (loc && loc->symtab)
     {
-      struct symbol *sym 
-	= find_pc_sect_function (loc->address, loc->section);
+      const struct symbol *sym = loc->symbol;
+
+      if (sym == NULL)
+	sym = find_pc_sect_function (loc->address, loc->section);
+
       if (sym)
 	{
 	  uiout->text ("in ");
@@ -8743,6 +8746,7 @@ add_location_to_breakpoint (struct breakpoint *b,
   loc->gdbarch = loc_gdbarch;
   loc->line_number = sal->line;
   loc->symtab = sal->symtab;
+  loc->symbol = sal->symbol;
 
   set_breakpoint_location_function (loc,
 				    sal->explicit_pc || sal->explicit_line);