Add a test case for generic ~Escapable initialization.

This tests:

- CapturePromotion handling of mark_dependence

- AccessBase.storeBorrow

- Unknown mark_dependence uses.

Author: atrick

test/SILOptimizer/lifetime_dependence_diagnostics_generic.sil renamed to test/SILOptimizer/lifetime_dependence.sil

@@ -14,6 +14,8 @@
 @_silgen_name("imagineInt64")
 func imagineInt64() -> Builtin.Int64
 
+precedencegroup AssignmentPrecedence { assignment: true }
+
 protocol P {
   associatedtype E: ~Escapable
   borrowing func getE() -> _borrow(self) E
@@ -38,6 +40,27 @@ public func pbits_ret_concerete() -> Bits {
   return pbits.getDefault()
 }
 
+struct NCInt: ~Copyable {
+  var value: Builtin.Int64
+
+  init(_ value: Builtin.Int64) { self.value = value }
+}
+
+struct NEInt: ~Escapable {
+  let value: Builtin.Int64
+
+  init<O: ~Copyable & ~Escapable>(v: Builtin.Int64, o: borrowing O) -> _borrow(o) Self {
+    self.value = v
+    return self
+  }
+
+  // Test a generic storage owner.
+  init(borrowed: borrowing NCInt) -> _borrow(borrowed) Self {
+    self.init(v: borrowed.value, o: borrowed)
+    return self
+  }
+}
+
 public func consume_indirect<NE: ~Escapable>(ne: consuming NE) -> _consume(ne) NE {
   return ne
 }