Ensure that we always use lowercase function names, and that we do not
have spaces preceding open parentheses, for consistency.

The `STDCALL` option was removed; remove the (unreachable) error
message.

There's no need to make tracing opt-in; it should always be included.

macOS may support ENABLE_REPRODUCIBLE_BUILDS, allow users to opt-in to
it. (Especially since ENABLE_REPRODUCIBLE_BUILDS is not the default.)

Nobody knows what CLAR is.  The test building option should be
`BUILD_TESTS`.

GCC C11 warnings

open: input validation for empty segments in path