Bump uClibc from v1.0.48-7-gad21b95c9 to v1.0.50

[TommyMurphyTM1234]

Fix for this issue:

• make uclibc fails #1563

[TommyMurphyTM1234]

Just realised - maybe I should have run the test suite before and after bumping uClibc to sanity check the change?

Edit: but I'm not sure that work was ever done to allow the test suite to run for the Linux/uClibc toolchain?

• Add uClibc-ng support for NOMMU Linux builds #1475 (comment)

Edit 2: oh - and, of course, I can't run the "before" test suite anyway since the whole point of this PR is to bump uClibc to fix the broken build! I would have to go back to some earlier version of the various submodules that would build successfully first. I would prefer not to have to do that.

Edit 3: OK - so there is no support in the current Makefile[.in] to run the test suite for the Linux/uClibc (or Linux/musl) toolchain(s) so enabling that would be a separate issue/PR and consequently, at the moment, it's only possible to bump uClibc "blindly" with no sanity checking of the results. I don't know whether or not this might influence the decision to merge or not merge this PR?

[cmuellner]

Thanks for the PR!

Tests are not supported for uClibc at this point.
So, all we need is a working build process (which is the whole purpose of this PR).

I double-checked the git commit/tag.

[cmuellner]

LGTM

[TommyMurphyTM1234]

Thanks @cmuellner! 👍