WiiWad: Allow using WiiWad with more than just files

This adds a WiiWad constructor that takes a BlobReader, so that the
class can be used with more than just files from the host filesystem.

Required for using WiiWad with WADs from update partitions.

Source/Core/DiscIO/WiiWad.cpp

@@ -44,21 +44,18 @@ bool IsWiiWAD(BlobReader& reader)
 }
 }  // Anonymous namespace
 
-WiiWAD::WiiWAD(const std::string& name) : m_reader(CreateBlobReader(name))
+WiiWAD::WiiWAD(const std::string& name) : WiiWAD(CreateBlobReader(name))
-{
-  if (m_reader == nullptr)
-  {
-    m_valid = false;
-    return;
-  }
-
-  m_valid = ParseWAD();
-}
-
-WiiWAD::~WiiWAD()
 {
 }
 
+WiiWAD::WiiWAD(std::unique_ptr<BlobReader> blob_reader) : m_reader(std::move(blob_reader))
+{
+  if (m_reader)
+    m_valid = ParseWAD();
+}
+
+WiiWAD::~WiiWAD() = default;
+
 bool WiiWAD::ParseWAD()
 {
   if (!IsWiiWAD(*m_reader))

Source/Core/DiscIO/WiiWad.h

@@ -19,6 +19,7 @@ class WiiWAD
 {
 public:
   explicit WiiWAD(const std::string& name);
+  explicit WiiWAD(std::unique_ptr<BlobReader> blob_reader);
   ~WiiWAD();
 
   bool IsValid() const { return m_valid; }
@@ -32,7 +33,7 @@ public:
 private:
   bool ParseWAD();
 
-  bool m_valid;
+  bool m_valid = false;
 
   std::unique_ptr<BlobReader> m_reader;