pgsql: Fix some assorted compiler warnings on Windows.

Fix some assorted compiler warnings on Windows.

Don't overflow the result type of constant expressions.  Don't negate
unsigned types.  Define HAVE_STDBOOL_H for Visual C++ 2013 and later.

Thomas Munro
Reviewed-By: Michael Paquier and Tom Lane

Discussion: https://postgr.es/m/CAEepm%3D3%3DTDYEXUEcHpEx%2BTwc31wo7PA0oBAiNt6sWmq93MW02A%40mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b2328bf62b6465236e318d31a011ced5dccfd580

Modified Files
--------------
src/backend/replication/basebackup.c | 2 +-
src/bin/pgbench/pgbench.c            | 3 ++-
src/include/pg_config.h.win32        | 4 +++-
3 files changed, 6 insertions(+), 3 deletions(-)