[ownership] Change BorrowScopeIntroducingValue::{visit,gather}LocalScopeEndingUses to use isConsumingUse instead of checking for isa<EndBorrowInst>().

I am going to be adding support for branch insts/SILPhiArgument to be able to
merge borrow scopes. Thus, the end lifetime for a borrow scope introducing
value, may not be an end_borrow. Luckily, in both cases of br and end_borrow we
model the end of lifetime as a consuming use, so checking for a consuming use
will work both before/after the change.

Author: gottesmm

lib/SIL/OwnershipUtils.cpp

@@ -120,12 +120,12 @@ void BorrowScopeIntroducingValue::getLocalScopeEndingInstructions(
   case BorrowScopeIntroducingValueKind::SILFunctionArgument:
     llvm_unreachable("Should only call this with a local scope");
   case BorrowScopeIntroducingValueKind::BeginBorrow:
-    llvm::copy(cast<BeginBorrowInst>(value)->getEndBorrows(),
-               std::back_inserter(scopeEndingInsts));
-    return;
   case BorrowScopeIntroducingValueKind::LoadBorrow:
-    llvm::copy(cast<LoadBorrowInst>(value)->getEndBorrows(),
-               std::back_inserter(scopeEndingInsts));
+    for (auto *use : value->getUses()) {
+      if (use->isConsumingUse()) {
+	scopeEndingInsts.push_back(use->getUser());
+      }
+    }
     return;
   }
   llvm_unreachable("Covered switch isn't covered?!");
@@ -137,16 +137,10 @@ void BorrowScopeIntroducingValue::visitLocalScopeEndingUses(
   switch (kind) {
   case BorrowScopeIntroducingValueKind::SILFunctionArgument:
     llvm_unreachable("Should only call this with a local scope");
-  case BorrowScopeIntroducingValueKind::BeginBorrow:
-    for (auto *use : value->getUses()) {
-      if (isa<EndBorrowInst>(use->getUser())) {
-        visitor(use);
-      }
-    }
-    return;
   case BorrowScopeIntroducingValueKind::LoadBorrow:
+  case BorrowScopeIntroducingValueKind::BeginBorrow:
     for (auto *use : value->getUses()) {
-      if (isa<EndBorrowInst>(use->getUser())) {
+      if (use->isConsumingUse()) {
         visitor(use);
       }
     }