pgsql: gen_node_support.pl: improve error message for unclosed struct.

gen_node_support.pl: improve error message for unclosed struct.

This error message was 'runaway "struct_name"', which isn't all
that clear; I think 'could not find closing brace for "struct_name"'
is better. Also, provide the location of the struct start using the
script's usual '$file:$lineno' style.

Bug: #18901
Reported-by: Clemens Ruck <clemens(dot)ruck(at)t-online(dot)de>
Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/18901-424272abe01357e6@postgresql.org

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/eaf582806c0d6b19c081c5afecd9ddb7003e6f80

Modified Files
--------------
src/backend/nodes/gen_node_support.pl | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)