Put back mistakenly removed #include.

In commit 4dbcb3f84 I removed some code from parse_coerce.c, and also
removed some apparently-no-longer-needed #includes.  But removing
datum.h broke some not-compiled-by-default code.

Discussion: https://postgr.es/m/20200407205436.pyjhddw5bn5upvsu@development

diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c
index 6cab20d09a10a1d23645fa5ccf20836847280c1f..1b11cf731ced9f7979807e585cdab55ba12757cf 100644 (file)
--- a/src/backend/parser/parse_coerce.c
+++ b/src/backend/parser/parse_coerce.c
@@ -25,6 +25,7 @@
 #include "parser/parse_relation.h"
 #include "parser/parse_type.h"
 #include "utils/builtins.h"
+#include "utils/datum.h"               /* needed for datumIsEqual() */
 #include "utils/lsyscache.h"
 #include "utils/syscache.h"
 #include "utils/typcache.h"