The new meson-test rule in t/Makefile causes a syntax error when the
default shell does not support non-standard process substitution:

  make[1]: Entering directory '/src/git/t'
  rm -f -r 'test-results'
  /bin/sh: 10: Syntax error: "(" unexpected
  make[1]: *** [Makefile:119: check-meson] Error 2

Due to this line:

  diff -u <(echo "$$meson_tests") <(echo "$$actual_tests");

This can of course be worked around with 'make test SHELL=/bin/bash',
but is that expected?

Kind regards,
Andy