PPC: remove indirection from struct pd_reg

The longest register name is 5 characters (plus a nul one), so using a
4- or 8-byte pointer to get at it is neither space nor time efficient.
Embed the names right into the array. For PIE this also reduces the
number of base relocations in the final image.

gas/config/tc-ppc.c

@@ -279,7 +279,7 @@ const pseudo_typeS md_pseudo_table[] =
 /* Structure to hold information about predefined registers.  */
 struct pd_reg
   {
-    const char *name;
+    char name[6];
     unsigned short value;
     unsigned short flags;
   };