[lldb][NFC] Implement llvm-style RTTI for DWARFASTParser

(cherry picked from commit 2cc3dc4)

Author: augusto2112

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParser.h

@@ -26,6 +26,9 @@ class SymbolFileDWARF;
 
 class DWARFASTParser {
 public:
+  enum class Kind { DWARFASTParserClang, DWARFASTParserSwift };
+  DWARFASTParser(Kind kind) : m_kind(kind) {}
+
   virtual ~DWARFASTParser() = default;
 
   virtual lldb::TypeSP ParseTypeFromDWARF(const lldb_private::SymbolContext &sc,
@@ -64,6 +67,11 @@ class DWARFASTParser {
                       const lldb_private::ExecutionContext *exe_ctx = nullptr);
 
   static lldb::AccessType GetAccessTypeFromDWARF(uint32_t dwarf_accessibility);
+
+  Kind GetKind() const { return m_kind; }
+
+private:
+  const Kind m_kind;
 };
 
 #endif // LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DWARFASTPARSER_H

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

@@ -61,7 +61,8 @@ using namespace lldb;
 using namespace lldb_private;
 using namespace lldb_private::dwarf;
 DWARFASTParserClang::DWARFASTParserClang(TypeSystemClang &ast)
-    : m_ast(ast), m_die_to_decl_ctx(), m_decl_ctx_to_die() {}
+    : DWARFASTParser(Kind::DWARFASTParserClang), m_ast(ast),
+      m_die_to_decl_ctx(), m_decl_ctx_to_die() {}
 
 DWARFASTParserClang::~DWARFASTParserClang() = default;
 

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h

@@ -218,6 +218,10 @@ class DWARFASTParserClang : public DWARFASTParser {
   // module.
   lldb::ModuleSP GetModuleForType(const DWARFDIE &die);
 
+  static bool classof(const DWARFASTParser *Parser) {
+    return Parser->GetKind() == Kind::DWARFASTParserClang;
+  }
+
 private:
   struct FieldInfo {
     uint64_t bit_size = 0;