Update for llvm change to add pdb namespace.

r268544 moves all PDB reading code into a pdb namespace,
so LLDB needs to be updated to take this into account.

llvm-svn: 268545
diff --git a/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.h b/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.h
index b8262014..ca425c1 100644
--- a/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.h
+++ b/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.h
@@ -30,10 +30,13 @@
 
 namespace llvm
 {
+namespace pdb
+{
 class PDBSymbol;
 class PDBSymbolData;
 class PDBSymbolTypeBuiltin;
 }
+}
 
 class PDBASTParser
 {
@@ -42,11 +45,11 @@
     ~PDBASTParser();
 
     lldb::TypeSP
-    CreateLLDBTypeFromPDBType(const llvm::PDBSymbol &type);
+    CreateLLDBTypeFromPDBType(const llvm::pdb::PDBSymbol &type);
 
 private:
     bool
-    AddEnumValue(lldb_private::CompilerType enum_type, const llvm::PDBSymbolData &data) const;
+    AddEnumValue(lldb_private::CompilerType enum_type, const llvm::pdb::PDBSymbolData &data) const;
 
     lldb_private::ClangASTContext &m_ast;
     lldb_private::ClangASTImporter m_ast_importer;