Emit dummy statements for probes.d probes when disabled
When building without --enable-dtrace, emit dummy
do {} while (0)
statements for the stubbed-out TRACE_POSTGRESQL_foo() macros
instead of empty macros that totally elide the original probe
statement.
This fixes the
warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
introduced by
b94409a02f.
Author: Craig Ringer <craig.ringer@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/
20210504221531.cfvpmmdfsou6eitb%40alap3.anarazel.de