[SIL] Add hasPointerEscape(SILValue).

There is a preexisting function with this name that takes a
BorrowedValue.  The new function calls that preexisting function if a
BorrowedValue can be constructed from the SILValue.  Otherwise, it looks
for direct uses of the value which qualify as "pointer escapes".

Author: nate-chandler

include/swift/SIL/OwnershipUtils.h

@@ -122,6 +122,12 @@ inline bool isForwardingConsume(SILValue value) {
 
 bool hasPointerEscape(BorrowedValue value);
 
+/// Whether the specified OSSA-lifetime introducer has a pointer escape.
+///
+/// precondition: \p value introduces an OSSA-lifetime, either a BorrowedValue
+/// can be constructed from it or it's an owned value
+bool hasPointerEscape(SILValue value);
+
 /// Find leaf "use points" of \p guaranteedValue that determine its lifetime
 /// requirement. Return true if no PointerEscape use was found.
 ///

lib/SIL/Utils/OwnershipUtils.cpp

@@ -83,6 +83,23 @@ bool swift::hasPointerEscape(BorrowedValue value) {
   return false;
 }
 
+bool swift::hasPointerEscape(SILValue value) {
+  if (auto borrowedValue = BorrowedValue(value)) {
+    return hasPointerEscape(borrowedValue);
+  }
+  assert(value->getOwnershipKind() == OwnershipKind::Owned);
+  for (auto use : value->getUses()) {
+    switch (use->getOperandOwnership()) {
+    case OperandOwnership::PointerEscape:
+    case OperandOwnership::ForwardingUnowned:
+      return true;
+    default:
+      break;
+    }
+  }
+  return false;
+}
+
 bool swift::canOpcodeForwardInnerGuaranteedValues(SILValue value) {
   // If we have an argument from a transforming terminator, we can forward
   // guaranteed.