test: stop hardcoding /usr/bin/gcc

[thesamesam]

Many tests have lines like test/unittest/usdt/tst.guess32.sh:14:CC=/usr/bin/gcc. They should respect CC from the environment to allow testing with different GCC versions.

e.g. On my system, /usr/bin/gcc is usually GCC trunk, but I might want to compare GCC 14 with that to check for regressions.

[thesamesam]

The same is true for objdump and all such toolchain tools.

[kvanhees]

+1

[nickalcock]

Totally agreed. This was a short-term kludge of mine in 2011 -- it's long past time for it to get fixed properly. A nice boring job given how pervasive this is :)

[thesamesam]

I don't mind taking it. I already have a stack of other test fixes it might conflict with, even.

[ezannoni]

Do we have a patch for this?

[thesamesam]

No, I'm happy to do it, but I was hoping to have my test fixes in first (already sent). I can prepare the patches now but I was worried about conflicts.

[kvanhees]

I am looking at the patches already submitted to pull them in.

[nickalcock]

I'm afraid that's almost certain to clash like mad with c80d7eb which I'm getting reviewed now :(

[nickalcock]

That's in, so the clash has happened and things have settled down again.

[thesamesam]

Thanks Nick. I'll rebase and test it, then send it soon.

[ezannoni]

Sam, did you get a chance to do the rebase?

[thesamesam]

I've rebased it but not re-tested: devel...thesamesam:dtrace-utils:trivial-test-fixes.