fixup: added newline in front of \pnum

Co-authored-by: Jan Schultke <[email protected]>

Author: dietmarkuehl

source/exec.tex

@@ -6512,6 +6512,7 @@
 coroutine state of size \tcode{size}, and unspecified additional
 state necessary to ensure that \tcode{operator delete} can later
 deallocate this memory block with an allocator equal to \tcode{palloc}.
+
 \pnum
 \returns
 A pointer to the allocated storage.