was building a bad cfg for ThisIsNotAFunc

Former-commit-id: 77ebeb4997072778a68f295046c47f05c7e750d3

libIRDB/src/cfg/CFG.cpp

@@ -149,7 +149,8 @@ void ControlFlowGraph_t::Build(Function_t* func)
 	alloc_blocks(starts, insn2block_map);
 	build_blocks(insn2block_map);
 	/* record the entry block */
-	entry=insn2block_map[func->GetEntryPoint()];
+	if(func->GetEntryPoint())
+		entry=insn2block_map[func->GetEntryPoint()];
 
 	/* most functions are done now. */
 	/* however, if a function has a (direct) side entrance,