Fix SBFrame::FindValue for when only global variables exist.

[chaoren]

Summary

sc.block->AppendVariables(...) returns 0 if there are no arguments or local
variables, but we still need to check for global variables.

[clayborg]

Looks good.

source/API/SBFrame.cpp

if (target && process)
 
                 switch (value_type)
                 {
                 case eValueTypeVariableGlobal:      // global variable
                 case eValueTypeVariableStatic:      // static variable
                 case eValueTypeVariableArgument:    // function argument variables
                 case eValueTypeVariableLocal:       // function local variables
                     {
-                        SymbolContext sc (frame->GetSymbolContext (eSymbolContextBlock));
+                        SymbolContext sc(frame->GetSymbolContext(eSymbolContextBlock));
 
                         const bool can_create = true;
                         const bool get_parent_variables = true;
                         const bool stop_if_block_is_inlined_function = true;
 
-                        if (sc.block && sc.block->AppendVariables (can_create, 
-                                                                   get_parent_variables,
-                                                                   stop_if_block_is_inlined_function,
-                                                                   &variable_list))
-                        {
-                            if (value_type == eValueTypeVariableGlobal)
-                            {
-                                const bool get_file_globals = true;
-                                VariableList* frame_vars = frame->GetVariableList(get_file_globals);
-                                if (frame_vars)
-                                    frame_vars->AppendVariablesIfUnique(variable_list);
-                            }
-                            ConstString const_name(name);
-                            VariableSP variable_sp(variable_list.FindVariable(const_name,value_type));
-                            if (variable_sp)
-                            {
-                                value_sp = frame->GetValueObjectForFrameVariable (variable_sp, eNoDynamicValues);
-                                sb_value.SetSP (value_sp, use_dynamic);
-                                break;
-                            }
+                        if (sc.block)
+                            sc.block->AppendVariables(can_create,
+                                                      &variable_list);
+                            VariableList *frame_vars = frame->GetVariableList(get_file_globals);
+                        VariableSP variable_sp(variable_list.FindVariable(const_name, value_type));
+                            value_sp = frame->GetValueObjectForFrameVariable(variable_sp, eNoDynamicValues);
+                            sb_value.SetSP(value_sp, use_dynamic);
                         }
                     }
                     break;
 
                 case eValueTypeRegister:            // stack frame register value
                     {
                         RegisterContextSP reg_ctx (frame->GetRegisterContext());
                         if (reg_ctx)