Don't allow findInnerTransitiveGuaranteedUses to exit early.

Useful for inserting on-the-fly lexical borrow scopes to cover only
the known uses ignoring pointer escapes.

Author: atrick

lib/SIL/Utils/OwnershipUtils.cpp

@@ -91,7 +91,9 @@ bool swift::canOpcodeForwardOwnedValues(Operand *use) {
 // points. Transitively find all nested scope-ending instructions by looking
 // through nested reborrows. Nested reborrows are not use points.
 bool swift::findInnerTransitiveGuaranteedUses(
-    SILValue guaranteedValue, SmallVectorImpl<Operand *> *usePoints) {
+  SILValue guaranteedValue, SmallVectorImpl<Operand *> *usePoints) {
+
+  bool foundPointerEscape = false;
 
   auto leafUse = [&](Operand *use) {
     if (usePoints && use->getOperandOwnership() != OperandOwnership::NonUse) {
@@ -127,7 +129,9 @@ bool swift::findInnerTransitiveGuaranteedUses(
 
     case OperandOwnership::ForwardingUnowned:
     case OperandOwnership::PointerEscape:
-      return false;
+      leafUse(use);
+      foundPointerEscape = true;
+      break;
 
     case OperandOwnership::InstantaneousUse:
     case OperandOwnership::UnownedInstantaneousUse:
@@ -143,17 +147,18 @@ bool swift::findInnerTransitiveGuaranteedUses(
       break;
 
     case OperandOwnership::InteriorPointer:
-      return false;
-
 #if 0 // FIXME!!! Enable in a following commit that fixes RAUW
-      // If our base guaranteed value does not have any consuming uses (consider
-      // function arguments), we need to be sure to include interior pointer
-      // operands since we may not get a use from a end_scope instruction.
+      // If our base guaranteed value does not have any consuming uses
+      // (consider function arguments), we need to be sure to include interior
+      // pointer operands since we may not get a use from a end_scope
+      // instruction.
       if (InteriorPointerOperand(use).findTransitiveUses(usePoints)
           != AddressUseKind::NonEscaping) {
-        return false;
+        foundPointerEscape = true;
       }
 #endif
+      leafUse(use);
+      foundPointerEscape = true;
       break;
 
     case OperandOwnership::ForwardingBorrow: {
@@ -192,7 +197,7 @@ bool swift::findInnerTransitiveGuaranteedUses(
       break;
     }
   }
-  return true;
+  return !foundPointerEscape;
 }
 
 /// Find all uses in the extended lifetime (i.e. including copies) of a simple