Fixed the forward declaration issue that was present in the DWARF parser after
adding methods to C++ and objective C classes. In order to make methods, we
need the function prototype which means we need the arguments. Parsing these
could cause a circular reference that caused an  assertion.

Added a new typedef for the clang opaque types which are just void pointers:
lldb::clang_type_t. This appears in lldb-types.h.

This was fixed by enabling struct, union, class, and enum types to only get
a forward declaration when we make the clang opaque qual type for these
types. When they need to actually be resolved, lldb_private::Type will call
a new function in the SymbolFile protocol to resolve a clang type when it is
not fully defined (clang::TagDecl::getDefinition() returns NULL). This allows
us to be a lot more lazy when parsing clang types and keeps down the amount
of data that gets parsed into the ASTContext for each module. 

Getting the clang type from a "lldb_private::Type" object now takes a boolean
that indicates if a forward declaration is ok:

    clang_type_t lldb_private::Type::GetClangType (bool forward_decl_is_ok);
    
So function prototypes that define parameters that are "const T&" can now just
parse the forward declaration for type 'T' and we avoid circular references in
the type system.



git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@115012 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Expression/ClangFunction.cpp b/source/Expression/ClangFunction.cpp
index 4035479..aaff16d 100644
--- a/source/Expression/ClangFunction.cpp
+++ b/source/Expression/ClangFunction.cpp
@@ -83,7 +83,7 @@
     m_JITted (false)
 {
     m_function_addr = m_function_ptr->GetAddressRange().GetBaseAddress();
-    m_function_return_qual_type = m_function_ptr->GetReturnType().GetOpaqueClangQualType();
+    m_function_return_qual_type = m_function_ptr->GetReturnType().GetClangType();
 }
 
 //----------------------------------------------------------------------
@@ -153,7 +153,7 @@
         else
         {
             Value *arg_value = m_arg_values.GetValueAtIndex(i);
-            void *clang_qual_type = arg_value->GetOpaqueClangQualType ();
+            void *clang_qual_type = arg_value->GetClangType ();
             if (clang_qual_type != NULL)
             {
                 type_stdstr = ClangASTContext::GetTypeName(clang_qual_type);
@@ -322,7 +322,7 @@
         
         if (arg_value->GetValueType() == Value::eValueTypeHostAddress &&
             arg_value->GetContextType() == Value::eContextTypeOpaqueClangQualType &&
-            ClangASTContext::IsPointerType(arg_value->GetOpaqueClangQualType()))
+            ClangASTContext::IsPointerType(arg_value->GetClangType()))
             continue;
         
         const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx, m_clang_ast_context->getASTContext());