include <errno.h> where necessary
I'm not sure what's different about my build environment, but sysprof fails to compile for me with missing references to errno
(#45 (closed)). GCC even identifies the solution:
../src/tests/allocs-within-mark.c:210:19: error: ‘errno’ undeclared (first use in this function)
210 | int errsv = errno;
| ^~~~~
../src/tests/allocs-within-mark.c:27:1: note: ‘errno’ is defined in header ‘<errno.h>’; did you forget to ‘#include <errno.h>’?
26 | #include <sysprof.h>
+++ |+#include <errno.h>
This PR adds errno.h
where necessary, across tools, libsysprof, and tests.