Use getDeclaredMethods() so we can see non-public methods of classes

When we are translating a class that was built as part of the Swift module,
use getDeclaredMethods() so we also see non-public methods.

Part of issue swiftlang#106.

Samples/JavaKitSampleApp/Sources/JavaKitExample/com/example/swift/HelloSwift.java

@@ -27,8 +27,8 @@ public HelloSwift() {
         this.value = initialValue;
     }
 
-    public native int sayHello(int x, int y);
-    public native String throwMessageFromSwift(String message) throws Exception;
+    native int sayHello(int x, int y);
+    native String throwMessageFromSwift(String message) throws Exception;
 
     // To be called back by the native code
     public double sayHelloBack(int i) {

Sources/Java2SwiftLib/JavaTranslator.swift

@@ -239,10 +239,6 @@ extension JavaTranslator {
     // Members
     var members: [DeclSyntax] = []
 
-    // Members that are native and will instead go into a NativeMethods
-    // protocol.
-    var nativeMembers: [DeclSyntax] = []
-
     // Fields
     var staticFields: [Field] = []
     var enumConstants: [Field] = []
@@ -290,7 +286,6 @@ extension JavaTranslator {
             )
 
             if implementedInSwift {
-              nativeMembers.append(translated)
               return nil
             }
 
@@ -327,7 +322,6 @@ extension JavaTranslator {
             )
 
             if implementedInSwift {
-              nativeMembers.append(translated)
               return nil
             }
 
@@ -441,6 +435,37 @@ extension JavaTranslator {
       )
     }
 
+    // Members that are native and will instead go into a NativeMethods
+    // protocol.
+    var nativeMembers: [DeclSyntax] = []
+    if swiftNativeImplementations.contains(javaClass.getCanonicalName()) {
+      nativeMembers.append(
+        contentsOf: javaClass.getDeclaredMethods().compactMap {
+          $0.flatMap { method in
+            // FIXME: For now, ignore static methods
+            if method.isStatic {
+              return nil
+            }
+
+            if !method.isNative {
+              return nil
+            }
+
+            // Translate the method if we can.
+            do {
+              return try translateMethod(
+                method,
+                implementedInSwift: true
+              )
+            } catch {
+              logUntranslated("Unable to translate '\(fullName)' method '\(method.getName())': \(error)")
+              return nil
+            }
+          }
+        }
+      )
+    }
+
     if !nativeMembers.isEmpty {
       let protocolDecl: DeclSyntax =
         """

Sources/JavaKitReflection/JavaClass+Reflection.swift

@@ -29,6 +29,9 @@ extension JavaClass {
   @JavaMethod
   public func getCanonicalName() -> String
 
+  @JavaMethod
+  public func getDeclaredMethods() -> [Method?]
+
   @JavaMethod
   public func getMethods() -> [Method?]