[CopyPropagation] Canonicalize all values.

Previously, the lifetimes of only values which were copied were
canonicalized during the non-mandatory CopyPropagation pass.  The
mandatory pass (i.e. MandatoryCopyPropagation) has been disabled,
meaning that non-copied values lifetimes were  never canonicalized.  So
enable canonicalization of all lifetimes during regular CopyPropagation.

rdar://54335055

Author: nate-chandler

lib/SILOptimizer/Transforms/CopyPropagation.cpp

@@ -375,7 +375,7 @@ namespace {
 class CopyPropagation : public SILFunctionTransform {
   /// True if debug_value instructions should be pruned.
   bool pruneDebug;
-  /// True of all values should be canonicalized.
+  /// True if all values should be canonicalized.
   bool canonicalizeAll;
   /// If true, then borrow scopes will be canonicalized, allowing copies of
   /// guaranteed values to be optimized. Does *not* shrink the borrow scope.
@@ -588,7 +588,7 @@ SILTransform *swift::createMandatoryCopyPropagation() {
 }
 
 SILTransform *swift::createCopyPropagation() {
-  return new CopyPropagation(/*pruneDebug*/ true, /*canonicalizeAll*/ false,
+  return new CopyPropagation(/*pruneDebug*/ true, /*canonicalizeAll*/ true,
                              /*canonicalizeBorrows*/ EnableRewriteBorrows,
                              /*poisonRefs*/ false);
 }

test/SILOptimizer/copy_propagation.sil

@@ -36,15 +36,15 @@ sil [ossa] @takeOwnedCTwice : $@convention(thin) (@owned C, @owned C) -> ()
 sil [ossa] @takeGuaranteedC : $@convention(thin) (@guaranteed C) -> ()
 sil [ossa] @takeGuaranteedAnyObject : $@convention(thin) (@guaranteed AnyObject) -> ()
 
-// -O ignores this because there's no copy_value
+// -O hoists the destroy
 // -Onone hoists the destroy and adds a poison flag.
 //
 // CHECK-LABEL: sil [ossa] @testDestroyAfterCall : {{.*}} {
 // CHECK: bb0:
 // CHECK: [[ARG:%.*]] = apply
 // CHECK-ONONE:   destroy_value [poison] [[ARG]] : $B
-// CHECK:   apply
 // CHECK-OPT:   destroy_value [[ARG]] : $B
+// CHECK:   apply
 // CHECK-LABEL: } // end sil function 'testDestroyAfterCall'
 sil [ossa] @testDestroyAfterCall : $@convention(thin) () -> () {
 bb0: