ext/json/parser/prereq.mk: keep line numbers of ext/json/parser/parser.c
Follow up of 5717e55e9a7790c938afa694a9bf558c0e54bb83. Adding a header with newline broke linenos.
ext/json/parser/prereq.mk: keep line numbers of ext/json/parser/parser.c
Follow up of 5717e55e9a7790c938afa694a9bf558c0e54bb83.
Adding a header with newline broke linenos.