bpo-36356: pymain_exit_error() only call pymain_free() for exit (GH-12968)

Add _Py_INIT_HAS_EXITCODE() macro.
diff --git a/Include/cpython/coreconfig.h b/Include/cpython/coreconfig.h
index c1a7298..ed2f09f 100644
--- a/Include/cpython/coreconfig.h
+++ b/Include/cpython/coreconfig.h
@@ -33,8 +33,10 @@
 #define _Py_INIT_NO_MEMORY() _Py_INIT_USER_ERR("memory allocation failed")
 #define _Py_INIT_EXIT(EXITCODE) \
     (_PyInitError){.prefix = NULL, .msg = NULL, .user_err = 0, .exitcode = (EXITCODE)}
+#define _Py_INIT_HAS_EXITCODE(err) \
+    (err.exitcode != -1)
 #define _Py_INIT_FAILED(err) \
-    (err.msg != NULL || err.exitcode != -1)
+    (err.msg != NULL || _Py_INIT_HAS_EXITCODE(err))
 
 /* --- _PyWstrList ------------------------------------------------ */
 
diff --git a/Modules/main.c b/Modules/main.c
index 6a7f735..68f0b99 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -570,7 +570,12 @@
 static void _Py_NO_RETURN
 pymain_exit_error(_PyInitError err)
 {
-    pymain_free();
+    if (_Py_INIT_HAS_EXITCODE(err)) {
+        /* If it's an error rather than a regular exit, leave Python runtime
+           alive: _Py_ExitInitError() uses the current exception and use
+           sys.stdout in this case. */
+        pymain_free();
+    }
     _Py_ExitInitError(err);
 }
 
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ae2d0bf..d93fe06 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -2172,7 +2172,7 @@
 void _Py_NO_RETURN
 _Py_ExitInitError(_PyInitError err)
 {
-    if (err.exitcode >= 0) {
+    if (_Py_INIT_HAS_EXITCODE(err)) {
         exit(err.exitcode);
     }
     else {