Add meson test driver

[matoro]

Switches tests to use "meson test" instead of a shell script. This also means that they now fully respect user-specified toolchain (e.g. clang compiler, custom CFLAGS, etc). Running C++ test is conditional on enabling INIReader support in the build.

 1/16 test_multi                               OK              0.05s
 2/16 test_multi_max_line                      OK              0.04s
 3/16 test_single                              OK              0.04s
 4/16 test_disallow_inline_comments            OK              0.03s
 5/16 test_stop_on_first_error                 OK              0.03s
 6/16 test_handler_lineno                      OK              0.02s
 7/16 test_heap                                OK              0.06s
 8/16 test_string                              OK              0.06s
 9/16 test_heap_max_line                       OK              0.05s
10/16 test_heap_realloc                        OK              0.05s
11/16 test_heap_realloc_max_line               OK              0.05s
12/16 test_heap_string                         OK              0.04s
13/16 test_call_handler_on_new_section         OK              0.04s
14/16 test_allow_no_value                      OK              0.03s
15/16 test_alloc                               OK              0.02s
16/16 test_INIReaderExample                    OK              0.02s

Ok:                 16
Expected Fail:      0
Fail:               0
Unexpected Pass:    0
Skipped:            0
Timeout:            0

[benhoyt]

I appreciate your efforts here. However, I'd rather not require meson as part of the test process of inih, partly because it's a tool I'm not at all familiar with so can't effectively review, and partly because I don't want me or others working on inih to have to install a separate tool (meson) to run the tests.

[matoro]

I appreciate your efforts here. However, I'd rather not require meson as part of the test process of inih, partly because it's a tool I'm not at all familiar with so can't effectively review, and partly because I don't want me or others working on inih to have to install a separate tool (meson) to run the tests.

Thank you for looking; would you be interested in accepting if I restored the original shell scripts so that both methods can coexist? Of course they could get out of sync, I understand if you'd rather not due to that concern.

[benhoyt]

Yes, actually, I'd be willing for them to coexist - good idea.

[benhoyt]

I also realised we should run the CI workflow on PR branches - feel free to make that change too.

[benhoyt]

Oh wait, I guess we do already.

[benhoyt]

Nice, this is much cleaner, thanks! One minor suggestion, take it or leave it.