[region-isolation] Add support for load_unowned.

Author: gottesmm

lib/SILOptimizer/Analysis/RegionAnalysis.cpp

@@ -2262,6 +2262,7 @@ CONSTANT_TRANSLATION(ClassMethodInst, Assign)
 CONSTANT_TRANSLATION(ObjCMethodInst, Assign)
 CONSTANT_TRANSLATION(SuperMethodInst, Assign)
 CONSTANT_TRANSLATION(ObjCSuperMethodInst, Assign)
+CONSTANT_TRANSLATION(LoadUnownedInst, Assign)
 
 // These instructions are in between look through and a true assign. We should
 // probably eventually treat them as look through but we haven't done the work
@@ -2462,7 +2463,6 @@ CONSTANT_TRANSLATION(ObjCExistentialMetatypeToObjectInst, Unhandled)
 CONSTANT_TRANSLATION(WeakCopyValueInst, Unhandled)
 CONSTANT_TRANSLATION(StrongCopyWeakValueInst, Unhandled)
 CONSTANT_TRANSLATION(StrongCopyUnmanagedValueInst, Unhandled)
-CONSTANT_TRANSLATION(LoadUnownedInst, Unhandled)
 CONSTANT_TRANSLATION(ValueMetatypeInst, Unhandled)
 CONSTANT_TRANSLATION(ExistentialMetatypeInst, Unhandled)
 CONSTANT_TRANSLATION(InitExistentialValueInst, Unhandled)

test/Concurrency/transfernonsendable_instruction_matching.sil

@@ -1587,3 +1587,21 @@ bb0:
   %9999 = tuple ()
   return %9999 : $()
 }
+
+sil [ossa] @load_unowned_test : $@async @convention(thin) () -> () {
+bb0:
+  %constructFn = function_ref @constructNonSendableKlass : $@convention(thin) () -> @owned NonSendableKlass
+  %value = apply %constructFn() : $@convention(thin) () -> @owned NonSendableKlass
+  %a = alloc_stack $@sil_unowned NonSendableKlass
+  store_unowned %value to [init] %a : $*@sil_unowned NonSendableKlass
+
+  %transferNonSendableKlass = function_ref @transferNonSendableKlass : $@convention(thin) @async (@guaranteed NonSendableKlass) -> ()
+  apply [caller_isolation=nonisolated] [callee_isolation=global_actor] %transferNonSendableKlass(%value) : $@convention(thin) @async (@guaranteed NonSendableKlass) -> () // expected-warning {{transferring value of non-Sendable type 'NonSendableKlass' from nonisolated context to global actor '<null>'-isolated context}}
+
+  %b = load_unowned [take] %a : $*@sil_unowned NonSendableKlass // expected-note {{access here could race}}
+  destroy_value %b : $NonSendableKlass
+  destroy_value %value : $NonSendableKlass
+  dealloc_stack %a : $*@sil_unowned NonSendableKlass
+  %9999 = tuple ()
+  return %9999 : $()
+}