Revert "Remove #if hasFeature(ImplicitOpenExistentials) block"

This reverts commit 73f1f68.

Author: sidepelican

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+NativeTranslation.swift

@@ -1319,6 +1319,7 @@ extension JNISwift2JavaGenerator {
 
         let existentialType = SwiftKitPrinting.renderExistentialType(protocolTypes)
 
+        // TODO: Remove the _openExistential when we decide to only support language mode v6+
         printer.print(
           """
           guard let \(inner)TypeMetadataPointer$ = UnsafeRawPointer(bitPattern: Int(Int64(fromJNI: \(typeMetadataVariableName), in: environment))) else {
@@ -1328,7 +1329,14 @@ extension JNISwift2JavaGenerator {
           guard let \(inner)RawPointer$ = UnsafeMutableRawPointer(bitPattern: Int(Int64(fromJNI: \(inner), in: environment))) else {
             fatalError("\(inner) memory address was null")
           }
+          #if hasFeature(ImplicitOpenExistentials)
           let \(existentialName) = \(inner)RawPointer$.load(as: \(inner)DynamicType$) as! \(existentialType)
+          #else
+          func \(inner)DoLoad<Ty>(_ ty: Ty.Type) -> \(existentialType) {
+            \(inner)RawPointer$.load(as: ty) as! \(existentialType)
+          }
+          let \(existentialName) = _openExistential(\(inner)DynamicType$, do: \(inner)DoLoad)
+          #endif
           """
         )
         return existentialName

Tests/JExtractSwiftTests/JNI/JNIProtocolTests.swift

@@ -140,7 +140,14 @@ struct JNIProtocolTests {
             guard let xpointer$RawPointer$ = UnsafeMutableRawPointer(bitPattern: Int(Int64(fromJNI: xpointer$, in: environment))) else {
               fatalError("xpointer$ memory address was null")
             }
+            #if hasFeature(ImplicitOpenExistentials)
             let xpointer$Existential$ = xpointer$RawPointer$.load(as: xpointer$DynamicType$) as! (any SomeProtocol)
+            #else
+            func xpointer$DoLoad<Ty>(_ ty: Ty.Type) -> (any SomeProtocol) {
+              xpointer$RawPointer$.load(as: ty) as! (any SomeProtocol)
+            }
+            let xpointer$Existential$ = _openExistential(xpointer$DynamicType$, do: xpointer$DoLoad)
+            #endif
             xswiftObject$ = xpointer$Existential$
           }
           else {
@@ -271,7 +278,14 @@ struct JNIProtocolTests {
             guard let xpointer$RawPointer$ = UnsafeMutableRawPointer(bitPattern: Int(Int64(fromJNI: xpointer$, in: environment))) else {
               fatalError("xpointer$ memory address was null")
             }
+            #if hasFeature(ImplicitOpenExistentials)
             let xpointer$Existential$ = xpointer$RawPointer$.load(as: xpointer$DynamicType$) as! (any (SomeProtocol & B))
+            #else
+            func xpointer$DoLoad<Ty>(_ ty: Ty.Type) -> (any (SomeProtocol & B)) {
+              xpointer$RawPointer$.load(as: ty) as! (any (SomeProtocol & B))
+            }
+            let xpointer$Existential$ = _openExistential(xpointer$DynamicType$, do: xpointer$DoLoad)
+            #endif
             xswiftObject$ = xpointer$Existential$
           }
           else {