Reorder the test suite so that low level features are tested

Reorder the test suite so that low level features are tested
before high level ones.
* tests/semantics.at (AC_CONFIG_FILES, HEADERS, LINKS and COMMANDS):
(missing templates): Move to...
* tests/torture.at: here.
Reorder the file so that the torture test is last.
* tests/semantics.at (AC_TRY_LINK_FUNC, AC_PROG_CPP with warnings)
(AC_PROG_CPP without warnings): Move to...
* tests/compile.at: here, new file.
* tests/suite.at: Run `torture' and then `compile' before
`semantics'.