Added a feature where registers can be referred to
using special $-variables from expressions.

(lldb) expr $rip

These variables are available for reading and
writing.


git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@120367 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Expression/ClangASTSource.cpp b/source/Expression/ClangASTSource.cpp
index e808a04..95a35b9 100644
--- a/source/Expression/ClangASTSource.cpp
+++ b/source/Expression/ClangASTSource.cpp
@@ -132,6 +132,8 @@
 
 clang::NamedDecl *NameSearchContext::AddVarDecl(void *type) {
     IdentifierInfo *ii = m_decl_name.getAsIdentifierInfo();
+    
+    assert (type && "Type for variable must be non-NULL!");
         
     clang::NamedDecl *Decl = VarDecl::Create(m_ast_source.m_ast_context, 
                                              const_cast<DeclContext*>(m_decl_context),