[CanOSSALifetime] Respect lexical lifetimes flag.

Don't respect deinit barriers when canonicalizing if lexical lifetimes
are disabled.

Author: nate-chandler

include/swift/SILOptimizer/Utils/CanonicalizeOSSALifetime.h

@@ -396,6 +396,13 @@ class CanonicalizeOSSALifetime final {
   UserRange getUsers() const { return liveness->getAllUsers(); }
 
 private:
+  bool respectsDeinitBarriers() const {
+    if (!currentDef->isLexical())
+      return false;
+    auto &module = currentDef->getFunction()->getModule();
+    return module.getASTContext().SILOpts.supportsLexicalLifetimes(module);
+  }
+
   void recordDebugValue(DebugValueInst *dvi) { debugValues.insert(dvi); }
 
   void recordConsumingUse(Operand *use) {

lib/SILOptimizer/Utils/CanonicalizeOSSALifetime.cpp

@@ -1125,7 +1125,7 @@ bool CanonicalizeOSSALifetime::computeLiveness() {
     clear();
     return false;
   }
-  if (currentDef->isLexical()) {
+  if (respectsDeinitBarriers()) {
     extendLivenessToDeinitBarriers();
   }
   if (accessBlockAnalysis) {