Swift SIL: add some APIs

* `Options.assertConfiguration`
* `Argument.isIndirectResult`
* in `Function`: `selfArgument`, `isTransparent`, `performanceConstraints` and `inlineStrategy`
* `BuiltinInst.substitutionMap`
* `SubstitutionMap.replacementTypes`
* `Type.canBeClass`

SwiftCompilerSources/Sources/SIL/SubstitutionMap.swift

@@ -24,4 +24,9 @@ public struct SubstitutionMap {
   }
 
   public var isEmpty: Bool { bridged.empty() }
+
+  public var replacementTypes: OptionalTypeArray {
+    let types = BridgedTypeArray.fromReplacementTypes(bridged)
+    return OptionalTypeArray(bridged: types)
+  }
 }