rdmd_test: simplify flag for specifying default compiler

[WebDrake]

Since it seems there are some use-cases where it is unavoidable to run rdmd_test directly, it's nice if we can reduce the amount of typing required to do so.

Besides the rdmd executable itself, the only other obligatory argument to the test suite is the default compiler expected to be used by rdmd. This patch shortens the long option to --default-compiler and allows an equivalent single-character -D option, so that usage can now be of the form:

rdmd_test -D <default-compiler> <path-to-rdmd-executable>

The posix.mak and win32.mak makefiles have been updated accordingly.

[dlang-bot]

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[WebDrake]

Sorry about earlier test failure: I forgot to tweak win32.mak ;-) Fixed now.

[WebDrake]

This time the test failure looks unrelated to the code. Is there some way to auto-trigger a fresh test from the PR? (I forget... :-\ )

[wilzbach]

git commit --amend or being a member of the dlang GH organization. With the latter your can directly restart the builds at Travis. I don't know why they don't allow it for the other (maybe to avoid over-using the quota of an organization?) - it's a bit silly because you could do this manually too. Anyhow, I restarted the failing build for you.

[WebDrake]

Some CI setups have hooks that allow PR authors (or maintainers) to trigger fresh builds via a comment "Test this please" or similar. Could be convenient?

Anyway, thanks :-)

[wilzbach]

Yes, we plan to do this, e.g. https://github.com/dlang-bots/dlang-bot/pull/109 or https://github.com/dlang-bots/dlang-bot/issues/190, but there's only so much one can do in one "day". (especially if some part of it is taken up by low-impact discussions ;-)).