Optimizer: add the FunctionPassContext.completeLifetime(of: Value) utility

Implemented by bridging the OSSALifetimeCompletion utility

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/PassManager/Context.swift

@@ -422,6 +422,14 @@ struct FunctionPassContext : MutatingContext {
 
       return buildFn(specializedFunction, nestedFunctionPassContext)
   }
+
+  /// Makes sure that the lifetime of `value` ends at all control flow paths, even in dead-end blocks.
+  /// Inserts destroys in dead-end blocks if those are missing.
+  func completeLifetime(of value: Value) {
+    if _bridged.completeLifetime(value.bridged) {
+      notifyInstructionsChanged()
+    }
+  }
 }
 
 struct SimplifyContext : MutatingContext {

include/swift/SILOptimizer/OptimizerBridging.h

@@ -397,6 +397,8 @@ struct BridgedPassContext {
                                                         SwiftInt paramCount,
                                                         BridgedFunction bridgedApplySiteCallee,
                                                         bool isSerialized) const;
+
+  bool completeLifetime(BridgedValue value) const;
 };
 
 bool FullApplySite_canInline(BridgedInstruction apply);

lib/SILOptimizer/PassManager/PassManager.cpp

@@ -21,6 +21,7 @@
 #include "swift/Demangling/Demangler.h"
 #include "swift/SIL/ApplySite.h"
 #include "swift/SIL/DynamicCasts.h"
+#include "swift/SIL/OSSALifetimeCompletion.h"
 #include "swift/SIL/SILBridging.h"
 #include "swift/SIL/SILCloner.h"
 #include "swift/SIL/SILFunction.h"
@@ -2041,6 +2042,16 @@ ClosureSpecializer_createEmptyFunctionWithSpecializedSignature(BridgedStringRef
   return {specializedApplySiteCallee};
 }
 
+bool BridgedPassContext::completeLifetime(BridgedValue value) const {
+  SILValue v = value.getSILValue();
+  SILFunction *f = v->getFunction();
+  DeadEndBlocks *deb = invocation->getPassManager()->getAnalysis<DeadEndBlocksAnalysis>()->get(f);
+  DominanceInfo *domInfo = invocation->getPassManager()->getAnalysis<DominanceAnalysis>()->get(f);
+  OSSALifetimeCompletion completion(f, domInfo, *deb);
+  auto result = completion.completeOSSALifetime(v, OSSALifetimeCompletion::Boundary::Availability);
+  return result == LifetimeCompletion::WasCompleted;
+}
+
 bool FullApplySite_canInline(BridgedInstruction apply) {
   return swift::SILInliner::canInlineApplySite(
       swift::FullApplySite(apply.unbridged()));