Add IRExecutionUnitSP to lldb-forward and use it instead of hand-rolling in place.

llvm-svn: 252129
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
index 35ad705..72c33fe 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
@@ -524,7 +524,7 @@
 Error
 ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_addr,
                                             lldb::addr_t &func_end,
-                                            std::shared_ptr<IRExecutionUnit> &execution_unit_sp,
+                                            lldb::IRExecutionUnitSP &execution_unit_sp,
                                             ExecutionContext &exe_ctx,
                                             bool &can_interpret,
                                             ExecutionPolicy execution_policy)