Alternate function to set valuetypes for ref-ness

Same method that ldloc.s uses, which incorporates the byref test.

Author: Joe Valenzuela

mono/mini/method-to-ir.c

@@ -12458,7 +12458,7 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
 				CHECK_OPSIZE (4);
 				n = read16 (ip + 2);
 				CHECK_LOCAL (n);
-				if ((ip [4] == CEE_LDFLD) && ip_in_bb (cfg, cfg->cbb, ip + 4) && header->locals [n]->type == MONO_TYPE_VALUETYPE && !header->locals [n]->byref) {
+				if ((ip [4] == CEE_LDFLD) && ip_in_bb (cfg, cfg->cbb, ip + 4) && MONO_TYPE_ISSTRUCT (header->locals [n])) {
 					/* Avoid loading a struct just to load one of its fields */
 					EMIT_NEW_LOCLOADA (cfg, ins, n);
 				} else {