make globals const

Author: iritkatriel

Include/internal/pycore_cfg.h

@@ -10,7 +10,7 @@ extern "C" {
 
 #include "pycore_opcode_utils.h"
 
-static _PyCompilerSrcLocation NO_LOCATION = {-1, -1, -1, -1};
+static const _PyCompilerSrcLocation NO_LOCATION = {-1, -1, -1, -1};
 
 typedef struct {
     int i_opcode;

Python/cfg.c

@@ -26,7 +26,7 @@ typedef _PyCfgBasicblock basicblock;
 typedef _PyCfgBuilder cfg_builder;
 typedef _PyCfgInstruction cfg_instr;
 
-static jump_target_label NO_LABEL = {-1};
+static const jump_target_label NO_LABEL = {-1};
 
 #define SAME_LABEL(L1, L2) ((L1).id == (L2).id)
 #define IS_LABEL(L) (!SAME_LABEL((L), (NO_LABEL)))