[NFC] OSSACompleteLifetime: Extracted function.

In preparation for adding a second caller.

Author: nate-chandler

lib/SIL/Utils/OSSALifetimeCompletion.cpp

@@ -419,6 +419,11 @@ static bool endLifetimeAtAvailabilityBoundary(SILValue value,
   return changed;
 }
 
+static bool endLifetimeAtBoundary(SILValue value,
+                                  SSAPrunedLiveness const &liveness,
+                                  OSSALifetimeCompletion::Boundary boundary,
+                                  DeadEndBlocks &deadEndBlocks);
+
 /// End the lifetime of \p value at unreachable instructions.
 ///
 /// Returns true if any new instructions were created to complete the lifetime.
@@ -431,23 +436,29 @@ bool OSSALifetimeCompletion::analyzeAndUpdateLifetime(SILValue value,
   };
   InteriorLiveness liveness(value);
   liveness.compute(domInfo, handleInnerScope);
+  // TODO: Rebuild outer adjacent phis on demand (SILGen does not currently
+  // produce guaranteed phis). See FindEnclosingDefs &
+  // findSuccessorDefsFromPredDefs. If no enclosing phi is found, we can create
+  // it here and use updateSSA to recursively populate phis.
+  assert(liveness.getUnenclosedPhis().empty());
+  return endLifetimeAtBoundary(value, liveness.getLiveness(), boundary,
+                               deadEndBlocks);
+}
 
+static bool endLifetimeAtBoundary(SILValue value,
+                                  SSAPrunedLiveness const &liveness,
+                                  OSSALifetimeCompletion::Boundary boundary,
+                                  DeadEndBlocks &deadEndBlocks) {
   bool changed = false;
   switch (boundary) {
-  case Boundary::Liveness:
-    changed |= endLifetimeAtLivenessBoundary(value, liveness.getLiveness(),
-                                             deadEndBlocks);
+  case OSSALifetimeCompletion::Boundary::Liveness:
+    changed |= endLifetimeAtLivenessBoundary(value, liveness, deadEndBlocks);
     break;
-  case Boundary::Availability:
-    changed |= endLifetimeAtAvailabilityBoundary(value, liveness.getLiveness(),
-                                                 deadEndBlocks);
+  case OSSALifetimeCompletion::Boundary::Availability:
+    changed |=
+        endLifetimeAtAvailabilityBoundary(value, liveness, deadEndBlocks);
     break;
   }
-  // TODO: Rebuild outer adjacent phis on demand (SILGen does not currently
-  // produce guaranteed phis). See FindEnclosingDefs &
-  // findSuccessorDefsFromPredDefs. If no enclosing phi is found, we can create
-  // it here and use updateSSA to recursively populate phis.
-  assert(liveness.getUnenclosedPhis().empty());
   return changed;
 }