[amdgcn] Reinitialize registers for every function

gcn_conditional_register_usage needs to be called for every function
to set the fixed registers depending on the kernel args currently
requested.

2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn.c (gcn_init_cumulative_args): Call reinit_regs.

From-SVN: r278299

gcc/ChangeLog

 2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>
 
-	gcc/
+	* config/gcn/gcn.c (gcn_init_cumulative_args): Call reinit_regs.
+
+2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>
+
 	* config/gcn/gcn.c (gcn_expand_prologue): Remove initialization and
 	prologue use of v0.
 	(print_operand_address): Use v1 for zero vector offset.

gcc/config/gcn/gcn.c

@@ -2438,6 +2438,8 @@ gcn_init_cumulative_args (CUMULATIVE_ARGS *cum /* Argument info to init */ ,
   cfun->machine->args = cum->args;
   if (!caller && cfun->machine->normal_function)
     gcn_detect_incoming_pointer_arg (fndecl);
+
+  reinit_regs ();
 }
 
 static bool