* lisp/progmodes/c-ts-mode.el (c-ts-mode--indent-styles): Make sure we
indent to great-grand-parent if inside an #ifdef...#endif block. If
grand-parent is root node, then don't indent one step.
(c-ts-mode--preproc-offset): New helper anchor function to calculate
indent offset.
* lisp/progmodes/c-ts-mode.el (c-ts-mode--indent-styles): Simplify
rules.
* test/lisp/progmodes/c-ts-mode-resources/indent-bsd.erts: New
testfile with bsd style indentation examples.
* test/lisp/progmodes/c-ts-mode-tests.el
(c-ts-mode-test-indentation-bsd): Add a test for the new style.
* test/lisp/progmodes/c-ts-mode-resources/filling.erts: New file.
* test/lisp/progmodes/c-ts-mode-resources/indent.erts: More tests.
* test/lisp/progmodes/c-ts-mode-tests.el:
(c-ts-mode-test-filling): new test.
* test/lisp/progmodes/c-ts-mode-resources/indent.erts: New .erts file
to test indentation of typical C constructs and prevent regression of
bug fixes.
* test/lisp/progmodes/c-ts-mode-tests.el: New file with c-ts-mode
tests.
