make xtensa_section_rename () take const char *

Xtensa uses it in several macros passing it a literal string, so its convenient
for the argument type to be const char *.  However some of the code in
symbols.c seems to assume tc_canonicalize_symbol_name () will return a non
const pointer, and some other target's implementations even modify the
argument, so it seems best to return a char * which means casting away const on
the argument when we return it instead of another string.

gas/ChangeLog:

2016-03-31  Trevor Saunders  <tbsaunde+binutils@tbsaunde.org>

	* config/tc-xtensa.c (struct rename_section_struct): Make old_name
	const.
	(xtensa_section_rename): Make argument type const char *.
	* config/tc-xtensa.h (xtensa_section_rename): Adjust.

1 files changed, 3 insertions, 3 deletions

diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index abefdd2..fe16659 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -13104,7 +13104,7 @@ copy_expr (expressionS *dst, const expressionS *src)
 
 struct rename_section_struct
 {
-  char *old_name;
+  const char *old_name;
   char *new_name;
   struct rename_section_struct *next;
 };
@@ -13177,7 +13177,7 @@ build_section_rename (const char *arg)
 
 
 char *
-xtensa_section_rename (char *name)
+xtensa_section_rename (const char *name)
 {
   struct rename_section_struct *r = section_rename;
 
@@ -13187,5 +13187,5 @@ xtensa_section_rename (char *name)
 	return r->new_name;
     }
 
-  return name;
+  return (char *) name;
 }