Style the "Reading symbols" message

The "Reading symbols" message does not use ui-out (perhaps it
should?), so this styles it using the low-level API.

gdb/ChangeLog
2018-12-28  Tom Tromey  <tom@tromey.com>

	* symfile.c (symbol_file_add_with_addrs): Style file name.

gdb/testsuite/ChangeLog
2018-12-28  Tom Tromey  <tom@tromey.com>

	* gdb.base/style.exp: Add test for styling of "Reading symbols"
	message.

gdb/ChangeLog

@@ -1,3 +1,7 @@
+2018-12-28  Tom Tromey  <tom@tromey.com>
+
+	* symfile.c (symbol_file_add_with_addrs): Style file name.
+
 2018-12-28  Tom Tromey  <tom@tromey.com>
 
 	* top.c (print_gdb_version): Style gdb version number.

gdb/symfile.c

@@ -58,6 +58,7 @@
 #include "cli/cli-utils.h"
 #include "common/byte-vector.h"
 #include "selftest.h"
+#include "cli/cli-style.h"
 
 #include <sys/types.h>
 #include <fcntl.h>
@@ -1110,7 +1111,11 @@ symbol_file_add_with_addrs (bfd *abfd, const char *name,
       if (deprecated_pre_add_symbol_hook)
 	deprecated_pre_add_symbol_hook (name);
       else
-	printf_filtered (_("Reading symbols from %s...\n"), name);
+	{
+	  puts_filtered (_("Reading symbols from "));
+	  fputs_styled (name, file_name_style.style (), gdb_stdout);
+	  puts_filtered ("...\n");
+	}
     }
   syms_from_objfile (objfile, addrs, add_flags);
 

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2018-12-28  Tom Tromey  <tom@tromey.com>
+
+	* gdb.base/style.exp: Add test for styling of "Reading symbols"
+	message.
+
 2018-12-28  Tom Tromey  <tom@tromey.com>
 
 	* gdb.base/style.exp: Add test for version number styling.

gdb/testsuite/gdb.base/style.exp

@@ -50,4 +50,8 @@ save_vars { env(TERM) } {
 
     gdb_test "" "\033\\\[35;1mGNU gdb.*\033\\\[m.*" \
 	"version is styled"
+
+    set quoted [string_to_regexp $binfile]
+    gdb_test "file $binfile" \
+	"Reading symbols from \033\\\[32m${quoted}\033\\\[m..." \
 }