stat_alloc casts

Casts from a void* just clutter the source.

	* ldexp.c (exp_intop, exp_bigintop, exp_relop, exp_binop, exp_trinop),
	(exp_unop, exp_nameop, exp_assop, exp_assert): Remove casts of
	stat_alloc return value.
	* ldlang.c (new_statement, new_afile, sort_def_symbol),
	(lang_memory_region_lookup, lang_memory_region_alias),
	(ldlang_add_undef, ldlang_add_require_defined, insert_pad),
	(lang_add_gc_name, lang_new_phdr): Likewise.
	* lexsup.c (set_segment_start): Likewise.

ld/lexsup.c

@@ -1734,7 +1734,7 @@ set_segment_start (const char *section, char *valstr)
       }
   /* There was no existing value so we must create a new segment
      entry.  */
-  seg = (segment_type *) stat_alloc (sizeof (*seg));
+  seg = stat_alloc (sizeof (*seg));
   seg->name = name;
   seg->value = val;
   seg->used = FALSE;