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/BaseNode.cs

@@ -0,0 +1,113 @@
+using System.IO;
+
+namespace Ryujinx.HLE.HOS.Diagnostics.Demangler.Ast
+{
+    public enum NodeType
+    {
+        CVQualifierType,
+        SimpleReferenceType,
+        NameType,
+        EncodedFunction,
+        NestedName,
+        SpecialName,
+        LiteralOperator,
+        NodeArray,
+        ElaboratedType,
+        PostfixQualifiedType,
+        SpecialSubstitution,
+        ExpandedSpecialSubstitution,
+        CtorDtorNameType,
+        EnclosedExpression,
+        ForwardTemplateReference,
+        NameTypeWithTemplateArguments,
+        PackedTemplateArgument,
+        TemplateArguments,
+        BooleanExpression,
+        CastExpression,
+        CallExpression,
+        IntegerCastExpression,
+        PackedTemplateParameter,
+        PackedTemplateParameterExpansion,
+        IntegerLiteral,
+        DeleteExpression,
+        MemberExpression,
+        ArraySubscriptingExpression,
+        InitListExpression,
+        PostfixExpression,
+        ConditionalExpression,
+        ThrowExpression,
+        FunctionParameter,
+        ConversionExpression,
+        BinaryExpression,
+        PrefixExpression,
+        BracedExpression,
+        BracedRangeExpression,
+        NewExpression,
+        QualifiedName,
+        StdQualifiedName,
+        DtOrName,
+        GlobalQualifiedName,
+        NoexceptSpec,
+        DynamicExceptionSpec,
+        FunctionType,
+        PointerType,
+        ReferenceType,
+        ConversionOperatorType,
+        LocalName,
+        CtorVtableSpecialName,
+        ArrayType
+    }
+
+    public abstract class BaseNode
+    {
+        public NodeType Type { get; protected set; }
+
+        public BaseNode(NodeType Type)
+        {
+            this.Type = Type;
+        }
+
+        public virtual void Print(TextWriter Writer)
+        {
+            PrintLeft(Writer);
+
+            if (HasRightPart())
+            {
+                PrintRight(Writer);
+            }
+        }
+
+        public abstract void PrintLeft(TextWriter Writer);
+
+        public virtual bool HasRightPart()
+        {
+            return false;
+        }
+
+        public virtual bool IsArray()
+        {
+            return false;
+        }
+
+        public virtual bool HasFunctions()
+        {
+            return false;
+        }
+
+        public virtual string GetName()
+        {
+            return null;
+        }
+
+        public virtual void PrintRight(TextWriter Writer) {}
+
+        public override string ToString()
+        {
+            StringWriter Writer = new StringWriter();
+
+            Print(Writer);
+
+            return Writer.ToString();
+        }
+    }
+}