Rewrite the C++ Demangler (#416)

* Rewrite the C++ Demangler

This new Demangler provides support to almost every possible mangled
symbols and should behaves like GNU c++filt.

It works on 98.9% of the sdk's symbols and 99.5%
of Puyo Puyo Tetris's symbols.

* Fix code style

* Fix noexcept enclosed expression parsing issues

* fix code style issues

Ryujinx.HLE/HOS/Diagnostics/Demangler/Ast/ForwardTemplateReference.cs

@@ -0,0 +1,36 @@
+using System.IO;
+
+namespace Ryujinx.HLE.HOS.Diagnostics.Demangler.Ast
+{
+    public class ForwardTemplateReference : BaseNode
+    {
+        // TODO: Compute inside the Demangler
+        public BaseNode Reference;
+        private int     Index;
+
+        public ForwardTemplateReference(int Index) : base(NodeType.ForwardTemplateReference)
+        {
+            this.Index = Index;
+        }
+
+        public override string GetName()
+        {
+            return Reference.GetName();
+        }
+
+        public override void PrintLeft(TextWriter Writer)
+        {
+            Reference.PrintLeft(Writer);
+        }
+
+        public override void PrintRight(TextWriter Writer)
+        {
+            Reference.PrintRight(Writer);
+        }
+
+        public override bool HasRightPart()
+        {
+            return Reference.HasRightPart();
+        }
+    }
+}