[SIL-opaque] Don't override arg value category.

Previously, when emitting block arguments, the value category of the
SILType was overridden to be address for indirect arguments.  With
opaque types, that distinction is made later during AddressLowering.  So
only do that when opaque types are disabled.

lib/SILGen/SILGenProlog.cpp

@@ -78,8 +78,9 @@ public:
         SGF.SGM.Types.getLoweredType(t, TypeExpansionContext::minimal());
     argType = argType.getCategoryType(argTypeConv.getCategory());
 
-    if (isInOut
-        || orig.getParameterConvention(SGF.SGM.Types) == AbstractionPattern::Indirect)
+    if (isInOut || (orig.getParameterConvention(SGF.SGM.Types) ==
+                        AbstractionPattern::Indirect &&
+                    SGF.SGM.M.useLoweredAddresses()))
       argType = argType.getCategoryType(SILValueCategory::Address);
 
     // Pop the next parameter info.