Move err_allocation_failed into error.c and make it available to

everyone.

src/error.c

@@ -10,6 +10,9 @@ error_t *const err_errorf_length = &(error_t){
     .message =
         "Formatting of another error failed to determine the error length"};
 
+error_t *err_allocation_failed =
+    &(error_t){.message = "Memory allocation failed"};
+
 error_t *errorf(const char *fmt, ...) {
     error_t *err = calloc(1, sizeof(error_t));
     if (err == nullptr)

src/error.h

@@ -18,4 +18,7 @@ static inline void error_free(error_t *err) {
     free(err);
 }
 
+/* Some global errors */
+extern error_t *err_allocation_failed;
+
 #endif // INCLUDE_SRC_ERROR_H_

src/lexer.c

@@ -20,9 +20,6 @@ error_t *err_eof =
 
 error_t *err_unknown_read = &(error_t){.message = "Unknown read error"};
 
-error_t *err_allocation_failed =
-    &(error_t){.message = "Memory allocation failed"};
-
 typedef bool (*char_predicate_t)(char);
 
 const char *lexer_token_id_to_cstr(lexer_token_id_t id) {